Add HikariCP implementation of the ConnectionPool

[jczuchnowski]

We want users to have an option of HikariCP connection pool in addition to ZIO SQL native one.

This should be a wrapper over HikariDataSource that would implement zio.sql.ConnectionPool interface.

Should be implemented in a separate sbt module (eg. jdbc-hickaricp), so that it can be optionally imported and not "pollute" the dependencies of the main module.

[sergeda]

I'd like to work on this