LT-15185: Crash when deleting WS in Vern & Anal

Fix a crash that occurs when a user deletes an Analysis WS that
is also a Vernacular WS.
- Hide WS's that the user deletes, but that are still in use
- Cancel deletion of WS's that the user re-adds before clicking OK
- Clean up a bit of code

Change-Id: Ifc9f23a433dac7cd8c2e350ff7f7606bc1e2e815