Only catch MySQL2 Errors in sinatra app

Connection to MySQL server is sometimes lost in sinatra app,
which was causing flakiness in our CI environments

Revert a query syntax error used for debugging
Change bootstrap conditions for mariad

- Now use go process to manage the start process/logic for mariadb
- Use file on persistent disk to maintain state knowledge
for starting mariadb

[finishes #73653220]
Add debugging via Sinatra app response

Help understand CI acceptance-tests flakiness