don't do table discovery on DROP. DROP falls back to "force"
approach when a table isn't found and will try to drop in all
engines anyway. That is, trying to discover in all engines before
the drop is redundant and may be expensive.
- IF EXISTS ends with a list of all not existing object, instead of a
separate note for every not existing object
- Produce a "Note" for all wrongly dropped objects
(like trying to do DROP SEQUENCE for a normal table)
- Do not write existing tables that could not be dropped to binlog
Other things:
MDEV-22820 Bogus "Unknown table" warnings produced upon attempt to drop
parent table referenced by FK
This was caused by an older version of this commit patch and later fixed
- Produce a "Note" for all wrongly dropped objects
(Like doing DROP VIEW on a table).
- IF EXISTS ends with a list of all not existing objects, instead of a
separate note for every not existing object.
Other things:
- Fixed bug where one could do CREATE TEMPORARY SEQUENCE multiple times
and create multiple temporary sequences with the same name.
