Emit schema mismatch errors

[Rentacookie]

TableMap events containing some schema information are sent before every row event on the BinLog. The tablemap event briefly describes the schema of the table for the row event that follows it. Unfortunately this description does not include the column names for the table. Instead this info is queried from the DB directly after which it is cached in memory for quick retrieval.

This poses a problem when older row events are received where the table schema at that point in time no longer matches the current schema. In such a case it may be impossible to consolidate the schema changes and the listener should emit the error so it can be handled downstream.

These changes ensures we emit these errors instead of crashing the listener.