changes to Snapshot and Binlog readers to allow for concurrent/partial running

Our plan for being able to add new tables to existing DBZ connectors involves effectively running a totally new snapshot and binlog reader for the tables in the new filter.
At present, the snapshot readers and binlog readers assume they will be the only snapshot/binlog process running and will be running everything that the connector is supposed to be managing (by reading from the config directly, for instance). This needs to be modified for us to be able to run these sub-connectors that manage only old filter info or new filter info.
The primary thing I imagine needs to be changed is that information about what filter info is being used should be explicitly passed in, rather than gotten from the current config. However, other things may need to be changed as well.