impr: Restore native macOS title bar double click gesture in borderless mode

[mentlerd]

Problem description

In borderless mode ImHex disables the standard macOS titlebar rendering and input processing. As a result double clicking the titlebar area does not resize the application's frame like native applications do.

Implementation description

ImGui elements consume input events in the order they are drawn. As a result by "drawing" an InvisibleButton over the content area of the titlebar we can catch unprocessed clicks in the titlebar area.

Connecting this button's double clicks to the native window is then a trivial endeavour.

Screenshots

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Additional things

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