Multi monitor support

Add multi monitor support.

Flatpak is available for testing

Seems to work properly, the only issue I've is that with GTK (actually because of Xorg) is not possible to go full screen on some chosen monitor, either 1 or all, so if you are so "unfortunate" to have 3 or more displays and want to use only 2 for Remmina, you cannot.

Implements #376 (closed) to add multi monitor support

Replaces !2043 (closed)

CC: @hugbe8 @danielMd2805

changed milestone to %v1.5.0

added PluginsRDP enhancement multimonitor labels

added 16 commits

• a7e15b0e...fce12336 - 11 commits from branch master
• 2f5c88ed - Adding multi monitor support
• 55c325b4 - Adding multi monitor support: monitor detection
• 8744c855 - Sending multiple layouts only if multimon is active
• ff1e4c8b - Merge branch 'rdp/multidisp' of gitlab.com:Remmina/Remmina into rdp/multidisp
• 5f883c3b - Adding multi monitor toolbar button

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added 1 commit

• 4dc4e0cf - Setting toolbar status updates for multi monitor

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added 26 commits

• 4dc4e0cf...bbe985f2 - 25 commits from branch master
• 453f5120 - Merging master branch in rdp/multidisp

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marked this merge request as ready

changed the description

mentioned in issue #376 (closed)

changed the description

changed the description

added 1 commit

• 42d65e02 - Moving the multi monitor icon up close to fullscreen

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added 16 commits

• 42d65e02...e46b8c1d - 8 commits from branch master
• c4dcb173 - Adding multi monitor support
• d429c38d - Adding multi monitor support: monitor detection
• 5dfc287d - Sending multiple layouts only if multimon is active
• 634010c7 - Adding multi monitor support
• de382ef1 - Sending multiple layouts only if multimon is active
• 6b95aed8 - Adding multi monitor toolbar button
• fbeab11e - Setting toolbar status updates for multi monitor
• bdf5f37e - Moving the multi monitor icon up close to fullscreen

Compare with previous version

mentioned in commit 61a44f95

merged

mentioned in commit c5a63bdf

mentioned in merge request !2213 (merged)

mentioned in issue #2862 (closed)