security: add object name to "access denied" error messages

Delete specifc access denied error code (ER_FUNCTION_ACCESS_DENIED,
ER_SPACE_ACCESS_DENIED, ER_FUNC_ACCESS_DENIED) and always
ER_ACCESS_DENIED code, which now contains object name and type

Pass operation type (create, drop, grant, revoke) to ER_ACCESS_DENIED.
Add a helper function schema_find_name() to schema.[h,cc].

In scope of gh-2911 "add triggers for audit log".

Heavily edited by @kostja