Multiple open to the side brings layout in a broken state

[isidorn]

Refs: #79845

1. Have a smaller vscode window
2. Open explorer and start clicking on the Open to the Side context menu command
3. Every editor is opened in a new group reducing the available horizontal space
4. When there is no more space the explorer is no longer visible and the layout is in a broken state since I can no longer click on any of the Sashes to resize 🐛

Notice on the gif that I am trying to find the sashes but am not able

[isidorn]

Note that I can more easily getting into the sashes are broken state by having more than 3 groups side by side. Somehow the sashes are always off then. Adding label bug.

[sbatten]

Making note of 2 regressions:

1. Open to side shifts the sidebar out of view
2. When in the broken state, if you can see the sidebar, the sash is disabled.

The sashes being broken within the editor part is not a regression it seems and we don't handle this super well in stable either, but better than this.

[sbatten]

@isidorn @joaomoreno I've pushed a fix here to make this better, but its not an ideal fix and also doesn't really fix everything. We should probably explore another option next iteration.

@joaomoreno feel free to revert if you think this fix is too hacky to keep

[octref]

Sashes now don't show, that's good, but I still want what terminal split does:

[sbatten]

@octref what makes this tricky today is that the editor can increase its size beyond the currently allotted space and should expand, but agreed that this would be an improvement.