WL#1088: Move all hardcoded messages of replication to share/errmsg.txt

Affects: Server-7.1   —   Status: Un-Assigned   —   Priority: Medium

The replication code uses a lot of hardcoded strings printed via
sql_print_error(). We could add messages in share/errmsg.txt instead of hardcoded.
Then it could return exact error messages to the client (instead of only writing
them to the error log).