Move delete table entities to state machine pattern

[MRayermannMSFT]

Do so to help expose progress of the deletes. Can investigate moving into a job handler, but only do so if there is not a negative change in performance.

[craxal]

No obvious performance issues are noticeable when run from the extension process, so no job handler was created. State pattern should be easy to move to one if performance issues are discovered later.