ovf import: disks: allow whitespaces in file path

Add a SAFE_CHAR_WITH_WHITESPACE_CLASS_RE sister variant of the shared
SAFE_CHAR_CLASS_RE shared regex to the base storage module, this use
case exist is a generic one after all, and use swap the untaint method
that parses the file a disk references to it.

Note that this is only the disk file name from inside the archive and
thus during the extraction to a staging/working directory, from there
it will be imported as volume allocated by the common storage system,
and thus follow our ordinary volume name scheme.

Improves disk detection when importing, e.g., the from upstream
provided GNS3 OVA.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

src/test/parse_volname_test.pm

@@ -108,6 +108,11 @@ my $tests = [
 	volname     => 'import/import.ova/disk.vmdk',
 	expected    => ['import', 'import.ova/disk.vmdk', undef, undef, undef, undef, 'ova+vmdk'],
     },
+    {
+	description => "Import, innner file of ova with whitespace in name",
+	volname     => 'import/import.ova/OS disk.vmdk',
+	expected    => ['import', 'import.ova/OS disk.vmdk', undef, undef, undef, undef, 'ova+vmdk'],
+    },
     {
 	description => "Import, innner file of ova",
 	volname     => 'import/import.ova/disk.raw',