[Feature] Ability to set type name when consuming from multiple topics.

[cgetzen]

Currently type.name is set at connector instantiation and is static, regardless of how many topics the connector is consuming from. I would like to either see an option to map topic name to ES doc type, or to have a mapping similar to topic.index.map -- maybe "type.index.map"? --- Alternatively, to speak to all meta-fields, maybe this info could be passed in with kafka headers. EX. What if we want to set the shard using "_routing"? https://www.elastic.co/guide/en/elasticsearch/reference/7.3/mapping-fields.html