GODT-1554 / 1555: Implement gRPC go service and Qt 5 frontend C++ app.

WIP: updates

WIP: cache on disk and autostart.

WIP: mail, keychain and more.

WIP: updated grpc version in go mod file.

WIP: user list.

WIP: RPC service placeholder

WIP: test C++ RPC client skeleton.

Other: missing license script update.

WIP: use Qt test framework.

WIP: test for app and login calls.

WIP: test for update & cache on disk calls.

WIP: tests for mail settings calls.

WIP: all client tests.

WIP: linter fixes.

WIP: fix missing license link.

WIP: update dependency_license script for gRPC and protobuf.

WIP: removed unused file.

WIP: app & login event streaming tests.

WIP: update event stream tests.

WIP: completed event streaming tests.

GODT-1554: qt C++ frontend skeleton.

WIP: C++ backend declaration.

wip: started drafting user model.

WIP: users. not functional.

WIP: invokable methods

WIP: Exception class + backend 'injection' into QML.

WIP: switch to VCPKG to ease multi-arch compilation,  C++ RPC client skeleton.

WIP: Renaming and reorganisation

WIP:introduced new 'grpc' go frontend.

WIP: Worker & Oveerseer for thread management.

WIP: added log to C++ app.

WIP: event stream architecture on Go side.

WIP: event parsing and streamer stopping.

WIP: Moved grpc to frontend subfolder + use vcpkg for gRPC and protobuf.

WIP: windows building ok

WIP: wired a few messages

WIP: more wiring.

WIP: Fixed imports after rebase on top of devel.

WIP: wired some bool and string properties.

WIP: more properties.

WIP: wired cache on disk stuff

WIP: connect event watcher.

WIP: login

WIP: fix showSplashScreen

WIP: Wired login calls.

WIP: user list.

WIP: Refactored main().

WIP: User retrieval .

WIP: no shared pointer in user model.

WIP: fixed user count.

WIP: cached goos.

WIP: Wired autostart

WIP: beta channel toggle wired.

WIP: User removal

WIP: wired theme

WIP: implemented configure apple mail.

WIP: split mode.

WIP: fixed user updates.

WIP: fixed Quit from tray icon

WIP: wired CurrentEmailClient

WIP: wired UseSSLForSMTP

WIP: wired change ports .

WIP: wired DoH. .

WIP: wired keychain calls.

WIP: wired autoupdate option.

WIP: QML Backend clean-up.

WIP: cleanup.

WIP: moved user related files in subfolder. .

WIP: User are managed using smart pointers.

WIP: cleanup.

WIP: more cleanup.

WIP: mail events forwarding

WIP: code inspection tweaks from CLion.

WIP: moved QML, cleanup, and missing copyright notices.

WIP: Backend is not QMLBackend.

Other: fixed issues reported by Leander. [skip ci]

internal/frontend/qt6/qml/Status.qml

@@ -0,0 +1,112 @@
+
+// Copyright (c) 2022 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
+
+import QtQuick 2.13
+import QtQuick.Layouts 1.12
+import QtQuick.Controls 2.12
+import QtQuick.Controls.impl 2.12
+
+import Proton 4.0
+import Notifications 1.0
+
+Item {
+    id: root
+
+    property var backend
+    property var notifications
+    property ColorScheme colorScheme
+
+    property int notificationWhitelist: NotificationFilter.FilterConsts.All
+    property int notificationBlacklist: NotificationFilter.FilterConsts.None
+
+    readonly property Notification activeNotification: notificationFilter.topmost
+
+    implicitHeight: children[0].implicitHeight + children[0].anchors.topMargin + children[0].anchors.bottomMargin
+    implicitWidth: children[0].implicitWidth + children[0].anchors.leftMargin + children[0].anchors.rightMargin
+
+    NotificationFilter {
+        id: notificationFilter
+
+        source: root.notifications ? root.notifications.all : undefined
+        whitelist: root.notificationWhitelist
+        blacklist: root.notificationBlacklist
+
+        onTopmostChanged: {
+            if (!topmost) {
+                image.source = "./icons/ic-connected.svg"
+                image.color = root.colorScheme.signal_success
+                label.text = qsTr("Connected")
+                label.color = root.colorScheme.signal_success
+                return;
+            }
+
+            image.source = topmost.icon
+            label.text = topmost.brief
+
+            switch (topmost.type) {
+                case Notification.NotificationType.Danger:
+                image.color = root.colorScheme.signal_danger
+                label.color = root.colorScheme.signal_danger
+                break;
+                case Notification.NotificationType.Warning:
+                image.color = root.colorScheme.signal_warning
+                label.color = root.colorScheme.signal_warning
+                break;
+                case Notification.NotificationType.Success:
+                image.color = root.colorScheme.signal_success
+                label.color = root.colorScheme.signal_success
+                break;
+                case Notification.NotificationType.Info:
+                image.color = root.colorScheme.signal_info
+                label.color = root.colorScheme.signal_info
+                break;
+            }
+        }
+    }
+
+    RowLayout {
+        anchors.fill: parent
+        spacing: 8
+
+        ColorImage {
+            id: image
+            width: 16
+            height: 16
+            sourceSize.width: width
+            sourceSize.height: height
+            source: "./icons/ic-connected.svg"
+            color: root.colorScheme.signal_success
+        }
+
+        Label {
+            colorScheme: root.colorScheme
+            id: label
+
+            Layout.fillHeight: true
+            Layout.fillWidth: true
+
+            wrapMode: Text.WordWrap
+
+            horizontalAlignment: Text.AlignLeft
+            verticalAlignment: Text.AlignVCenter
+
+            text: qsTr("Connected")
+            color: root.colorScheme.signal_success
+        }
+    }
+}