[TASK] Add action selector in toolbar in workspaces menu

Currently there are two selectors in the bottom toolbar of
the workspace module. One to handle stage changes on selected
elements and one for mass actions (publish, swap, discard) for
the whole workspace. To circumvent this, an additional selector
shall be added for record selections.

Resolves: #59898
Releases: 6.2, 6.3
Change-Id: I5991cc16a65ba5ac473ec380f534379ec925cad3
Reviewed-on: https://review.typo3.org/31273
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters