Tablename for deleted fields

#569240: Remove field ID from field table names had field ids appear only in tablenames for deleted-but-not-yet-purged fields: field_data_foo becomes field_data_foo_12 if the field is deleted.
This id that pops up at the end of the table still confuses people looking at their db, as #650710-1: Unassigned field is no longer deletable shows.

Once we accepted the idea of a table rename on field deletion, there's no reason for not pushing this one step further and clearly move those tables out of the way:
Attach patch does "field_data_foo -> field_deleted_data_12, field_revision_foo -> field_deleted_revision_12"