do not re-animate on three touch lateral swipe

[jtzero]

Doubtful this is the best way to do this, however, it appears to work

Resolves #185

Gnome 46

[matttbe]

@jtzero thank you for having looked at this!

This appears to work on GNOME Shell 48 as well.

[PeterJCLaw]

Thanks for having a go at a fix!

Confirming that this patch mostly works on Ubuntu 22.04.5 LTS, Gnome 42.9, Extension version 38. (I manually re-typed the patch on top of the local files, the only difference in the existing code seemed to be the base class which WorkspaceAnimationController extends from).

Keyboard navigation seems to work fine.

The horizontal swipe animation isn't perfect, though I'm not sure how much that's just the underlying animation. I do also sometimes see the double animation still.
Separately sometimes I also manage to swipe to a new desktop and then the windows from the previous one reappear. Somehow this is only the windows and not their entries elsewhere (e.g: I'm using https://github.com/home-sweet-gnome/dash-to-panel). Interacting with those windows caused a forced logout (I assume Gnome Shell crash; I'll try to grab logs if I can reproduce it) :(

I'm not sure how to test the vertical swipe animation -- for me a three finger vertical swipe controls up the Application switcher (upwards to show it, downwards to dismiss).

Finally, I think there might be a missing return in the else block? Though as keyboard interactions seemed to work fine this may be immaterial. (either way I've added this in my local changes)

Would be great to have this backported once merged, if that's possible.

[PeterJCLaw]

I do also sometimes see the double animation still.
Separately sometimes I also manage to swipe to a new desktop and then the windows from the previous one reappear. Somehow this is only the windows and not their entries elsewhere (e.g: I'm using https://github.com/home-sweet-gnome/dash-to-panel). Interacting with those windows caused a forced logout (I assume Gnome Shell crash; I'll try to grab logs if I can reproduce it) :(

Came up with a reproduce for these, though didn't follow through to the crash state. The key is that weird things happen if the swipe follows through all the way such that the new workspace is fully aligned with the screen.

For the double animation still being present, that happens for any ordinary pair of workspaces (tested left & right).

For the windows reappearing unexpectedly, that happens for a pair of workspaces which involve a wrap around from one side of the matrix to another (say, top left to bottom right). In these cases I don't get the double animation.