Remove restoring soft deleted entries part 1

There is no need to reuse deleted entries, because they will be archived after
db-archiving implementation. And restoring soft deleted entries produce some
problem with db-unique-keys implementation. So the best way is to remove it.

instance_type_access_add() method
Remove restoring soft deleted instance_type_access entries

instance_type_extra_specs_update_or_create() method
Remove restoring soft deleted instance_type_extra_specs entries
Add missing transaction

aggregate_host_add() method
Remove restoring soft deleted aggreagate_hosts entries
Add missing transaction

blueprint db-session-cleanup

Change-Id: Ida7db95233c40faacac55105650f52d42ad360c2
Merge "Remove restoring soft deleted entries part 1"