Allow to modify annotations from Signal/Image View ?

[PierreRaybaut]

Current behavior

Annotations are added and modified exclusively using the separate window view.

• Using the "View" > "View in a new window" menu entry:
• Or by double-clicking on the signal or image in Signal/Image Panel:
• Or using the context menu in Signal/Image Panel:

This opens a new window allowing to add/modify annotations:

Alternative behavior

We allow annotations to be at least modified directly from the Signal/Image View.

[PierreRaybaut]

For now, I think that the current behavior is a good compromise because it avoids any accidental modifications of the annotations. Besides, adding the ability to modify annotations from Signal/Image View would lead to complicated and/or cumbersome GUIs.

One of the cons of keeping the current behavior is that it might be counter intuitive to not be able to modify those annotations in the main view. The fact that annotations are still selectable does not help understand that we can't modify them from this view: this will be fixed (they will no longer be selectable, to help understand the user that any modification has to be done elsewhere).

Another fix has to be done: we need to hide/remove the "Item list" panel in the Signal/Image View: this panel can be shown by clicking on "Item list" in the plot context menu and allows to access all visible plot items.