FastPrimitivesCoder should be able to encode types from schema'd PCollections without encoding the schema

FastPrimitivesCoder should be able to check if we have a schema registered for a type, and encode/decode instances with the RowCoder for that schema.

Note that FastPrimitivesCoder will currently fail to encode some schema types, fixing BEAM-9574 will address those failures, but will be sub-optimal, since the schema will be encoded with every instance.