Make error messages from DROP TABLE and DROP TABLE IF EXISTS consistent

- 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

mysql-test/main/stack-crash.result

@@ -1,7 +1,6 @@
 drop table if exists t1,t2;
 Warnings:
-Note	1051	Unknown table 'test.t1'
-Note	1051	Unknown table 'test.t2'
+Note	1051	Unknown table 'test.t1,test.t2'
 CREATE TABLE t1 (
 `sspo_id` int(11) NOT NULL AUTO_INCREMENT,
 `sspo_uid` int(11) NOT NULL DEFAULT '0',