Hide the Publish and Merge operation links when they can't be performed

I wonder if we could re-purpose this issue to cover a new edge issue where you should publish a workspace if there is a sub workspace with changes in it. It leads to issue where content is locked.

Opened a pretty small MR to handle this. I'm looking for the comparable change needed in WSE next.

We can't handle #10 here. There isn't any status field on workspaces in core. I'll open a new bug for this sub workspace publish bug.

Even though a task seems like a change that should have some test coverage.