GH-1377: Extract move and zoom features from accessibility to own module

[haydar-metin]

What it does

Works on eclipse-glsp/glsp#1377

How to test

Use the arrow keys to move the viewport / elements.
Use +/- to zoom in and out.

Follow-ups

Changelog

• This PR should be mentioned in the changelog
• This PR introduces a breaking change (if yes, provide more details below for the changelog and the migration guide)

The move and zoom features have been moved to their own modules. They are now enabled by default.

[haydar-metin]

@tortmayr after some thought, do we even require tools for moving/zooming? Maybe moveElement would require it, but moving the viewport and zooming shouldn't need a tool or?

[tortmayr]

@haydar-metin I agree. Currently zooming/scrolling via mouse is provided by the viewportModule. This module bind the mouse listeners directly instead of using tools. This means that those listeners are always on (independent of the activation state of the tool manager). Listeners that provide the same functionality via keyboard should probably also be bound directly.
Otherwise we end up in an inconsistent state. (e.g. during edge creation zooming via mouse would be possible, but zooming via keyboard not (because default tools are disabled at that point).

So we should not use tools for zooming/moving.
For the move-tool its a different story, here a tool definitely make sense but maybe we should integrate this into the change bounds tool instead of having a separate tool just for keyboard movement

Thinking about it maybe it even makes sense to integrate the keyboard functionality for zooming/moving/scrolling directly into the corresponding default module (viewportModule, changeBoundsToolModule) instead of having extra a11y modules for them.
WDYT?

[haydar-metin]

@tortmayr sounds good to me! I did the following:

• MoveElementHandler (ActionHandler) moved to bounds, as we don't have a changeBounds container module.
• MoveElementKeyListener moved to change-bounds-tool
• MoveViewport*, Zoom** moved to viewport

[tortmayr]

@haydar-metin Thanks for providing this change.
If its ok for you I will take a look at this PR after the 2.3 release is completed (planned until the end of next week).
Since this PR only partially addresses eclipse-glsp/glsp#1377 and also introduces some changes to the protocol API we should probably not include it in the current release.
We can then use the next release cycle to further work on eclipse-glsp/glsp#1377 .