Support multiple schemas with Oracle LogMiner

The connector currently leverages a database.schema setting which effectively prevents the connector from supporting multiple schemas during streaming. The connector should ideally use the Filters to derive a valid list of schema names that are to be used during streaming when querying the LogMiner contents view. In addition, the schema name should be passed from the result-set row during processing of the mined entries rather than expecting this to be static based on database.schema as well.