Ability to choose the default schema (search_path)

I'm unable to choose the schema to use when connecting to the database. Currently I have to prepend the schema name before the table name in every query.

I also tried the following command and it didn't work.
`clientPtr->execSqlSync("SET search_path = $1", "my_schema");`

When creating a Postgres connection in other libraries, we usually use arguments like `options='-csearch_path=my_schema'` to specify the schema.

It would be good if there were an option in config.json to choose the default schema. The parameter could be either
`"schema": "my_schema"`
or
`"rdbms_options": "-csearch_path=my_schema"`