Rework how `config` table works in mysql database

DB table `config` stores everything in a single row. This poses an issue with mysql limitations on maximum row size. https://dev.mysql.com/doc/mysql-reslimits-excerpt/8.0/en/column-count-limit.html#row-size-limits

In particular:

The internal representation of a MySQL table has a maximum row size limit of 65,535 bytes, even if the storage engine is capable of supporting larger rows. BLOB and TEXT columns only contribute 9 to 12 bytes toward the row size limit because their contents are stored separately from the rest of the row. 

We are reaching this limit with `config` table.

Propose to redesign the way we store data, that currently resides in `config` table, to eliminate this issue altogether.