Retain compatibility with old annotation toolbar

With the new annotation toolbar apparently we have broken the habits of some users. In this issue I would like to specifically try to figure out if we can do something to mitigate this issue.

The main problematic points are:

1. The shortcuts of the quick annotations changed from 1, 2, 3, ... to Alt + 1, 2, 3, ...
2. The quick annotation tools are not always visible in their own toolbar. This implies that:
   • Users cannot rely anymore on their order to infer the shortcut number
   • Requires one more click to access them, thus making them slightly more difficult to access than the builtin annotations
3. It is impossible to open the Quick Annotation menu with a shortcut, even though it is possible to assign it a shortcut (this is related to ToggleAnnotationMenu, we can discuss it in #19 (closed))
4. It is more difficult to see what quick annotation tool is selected (one have to look at two icons instead of one in the annotation toolbar) because currently the selected quick annotation tool is not shown in the quick annotation menu.

Solution agreed on Okular BoF:

• Make the 'Quick annotation action' display the currently selected action (given that the action become checkable, it should also uncheck the currently selected mouse action as previously discussed)

• Do not show the builtin annotation toolbar when a quick annotation is selected

• Add an action that when added to the toolbar displays all the quick annotations. Not shown by default. This is a 'composite' action similar to the Page Number action.

  Pro:

  • Save vertical space not showing any toolbar and still allowing to access the quick annotations
  • Keep visual complexity low (only one toolbar)
  • Give flexibility to the user to build their own custom annotation toolbar, possibly mimicking Okular < 1.11.0

  Cons:

  • The user needs to manually configure the toolbar to have the same behavior of Okular < 1.11.0

BUG: 425438

BUG: 425598