Refactor: Adopt qt hierachical focus management

[ZhongYic00]

Reduce use of forceActiveFocus, use focusscope etc. to automatically pass focus along the item tree. Currently uses of forceActiveFocus lacks checking, may result in:

• passwordinput failed to get focus, but unset workspace's focus so focus is set to root content item
• greeter shows but later some surface becomes mapped so focus is robbed

Also fix that focus get lost when only there's one surface after switcher or some treeland controls get focus

based on https://github.com/vioken/waylib/pull/285

[deepin-ci-robot]

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