Embed a nice screensaver so we don't depend on XScreensaver

[andydotxyz]

Description:

Still needs:

• Inhibit when requested by movie players etc
• Multiple monitor support

Checklist:

• Tests included.
• Lint and formatter run with no errors.
• Tests all pass.
• Public APIs match existing style.

[coveralls]

Pull Request Test Coverage Report for Build 13619428951

Details

• 26 of 243 (10.7%) changed or added relevant lines in 9 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.5%) to 23.322%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/ui/menu.go	0	6	0.0%
internal/x11/wm/events.go	0	6	0.0%
internal/ui/desk.go	10	17	58.82%
internal/x11/wm/desk.go	0	9	0.0%
internal/ui/settings_ui.go	0	17	0.0%
internal/ui/embed_wm.go	13	34	38.24%
internal/ui/settings.go	3	33	9.09%
internal/x11/wm/screensaver.go	0	35	0.0%
internal/ui/screensaver.go	0	86	0.0%

Files with Coverage Reduction	New Missed Lines	%
internal/ui/settings_ui.go	1	0.0%

Totals
Change from base Build 13607336956:	-0.5%
Covered Lines:	1237
Relevant Lines:	5304

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💛 - Coveralls

[taigrr]

Looks like we kinda have half-support for multimonitor through xscreensaver right? Just not if xscreensaver isn't installed?

[andydotxyz]

Yes the xscreensaver plugin supports multi-monitor but the replacement with Fyne does not yet. Other than that it seems to be working quite well.