feat(sql): use a connection pool named "read" for some read operations in SqlExecutionRepository

[kirangodishala]

Introduce a read pool for some read-only database queries in SqlExecutionRepository. Enable this by configuring an additional connection pool named "read", like this:

sql:
  connectionPools:
    default:
      <...>
    read:
      jdbcUrl: jdbc:...
      user: orca_service
      password: 
      connectionTimeoutMs: 
      validationTimeoutMs: 
      maxPoolSize:
      minIdle:
      maxLifetimeMs:
      idleTimeoutMs:

Additional read-only database queries happen in places that expect to see "just-written" contents. They're not safe to convert to use the read replica until there's logic in place to be aware of replication lag, and wait until the read replica is up-to-date.

[dzhengg]

Could we include an example (maybe in one of the commit messages or the description) for how to configure orca to use a read pool?