Add osu! setting to control automatic minimising on focus loss in fullscreen mode

[Susko3]

Depends on:

• Add setting to control automatic minimising on focus loss in fullscreen mode osu-framework#6094
• framework bump

Adds the osu!-side setting to control FrameworkSetting.MinimiseOnFocusLossInFullscreen

• should equivalent to stable "Minimise on alt-tab during fullscreen"
• the setting checkbox is only visible when in fullscreen mode (some report that the SDL hint also affects borderless on linux - I've decided to ignore that)

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ConfineMouseTracker is updated to only override OsuSetting.ConfineMouseMode when clicking outside the window would minimise the window

• i.e. when in fullscreen and MinimiseOnFocusLossInFullscreen == true
• those who disable MinimiseOnFocusLossInFullscreen are likely to use multiple monitors and allowing the cursor to leave the window makes sense for that use case
• if confining is desired, the user can set ConfineMouseMode to Always
• the relevant setting is updated to reflect that, but I've decided to leave the tooltip as "Not applicable in full screen mode"

I can add tests for this to ConfineMouseTrackerTest, but I don't see much benefit as it's just testing the very basic ConfineMouseTracker logic.