Add DELETE Endpoint for deleting SILC Group Member

Add DELETE Endpoint for deleting SILC Group Member. The delete endpoint simply archives the member by setting archive property to true and moving the record to the archive database. You can override the http DELETE command or simply use PATCH!

Start at the SILC Group Member API endpoint and inspect how member records are stored and moved between databases. Confirm whether DELETE or PATCH is the existing convention, then implement archiving by setting the archive property to true and moving the record to the archive database.

Written by the indexing model from the issue text.