Add more fields to the SQL Error plugin

The current fields provided by the sql_error plugin are, in 10.11:

Time User Type Error_code: Error_message : Query

The 'User' includes the IP when connecting through TCP/IP
https://mariadb.com/kb/en/sql-error-log-plugin/ has more details.

The request is to add Thread_id directly after Time, similar to what we do in the error log.

When doing this task, it would be good to also enhance perror to print the text for all MariaDB server error messages (at least the English ones)

shell> perror 1000
Illegal error code: 1000

This will be helpful as in the near future we will add a link to the perror output to a KB article that explains the reason for the error in more detail.

As part of this task, we should also do MDEV-10295 Create a status counter for SQL_ERROR_LOG plugin as this is a trivial thing to do at the same time.