fix: SG-43096: Fix Playback buttons offset displacement

[deltag0]

fix: Fix Bottom Toolbar offset displacement

Summarize your change.

Changed toolbar UI to be designed in 3 boxes:

• left box
• center box
• right box
  instead of adding the components individually to the toolbar.

Describe the reason for the change.

Easier to position different areas of the toolbar, and no problem with offsets with new components to the toolbar nor positioning existing components.
Because the QT actions aren't added directly to the toolbar, a separate overflow function had to be created, and buttons created by plugins had new functions added to manage them.

Describe what you have tested and on which operating system.

• Tested that toolbar functionality works the same
• Tested that the playback buttons don't get displaced
• Tested the fix on layout mode

Add a list of changes, and note any that might need special attention during the review.

• Toolbar button overflow when resizing the window
• Toolbar buttons with pictures loaded and without
• When resizing the window, the button overflow behaviour is slightly different. Now, the Play/Resume buttons will always remain visible in the application

If possible, provide screenshots.