Add two separate toggles to control event loop pausing. This is required
to prevent cases where the bridge requests the event loop to be paused
but a sync process completes and resumes the event loop.
For the loop to resume now both states need to be set to false. This
will be removed once GODT-2848 is implemented.
Rather than having the services subscribe to each individual event type,
have only one subscriber for the whole event object. This spreads the
logic to the service through the `EventHandler` type.
This is important for the next stage where the IMAP service will be
required to apply events from the past.
Handles all IMAP related tasks. Unlike the previous iteration, this new
service automatically adds and removes users from Gluon by interfacing
with server manager.
