Prevent revoking QUERY access #270
Description
Describe the bug
In the past, QUERY access was linked to GRANT access. Because it is not allowed to remove your own GRANT access it was not possible to block yourself out of ThingsDB. Since QUERY is no longer linked, it is possible to lock yourself out by removing QUERY access. Therefore we should prevent this action.
To Reproduce
Remove QUERY access from the admin user. This is currently allowed as the admin user has GRANT privileges by default.
The admin user can no longer be used.
Expected behavior
Raise an exception when QUERY access from the current user will be removed.