Epic: none

Release note: none

…ning

Epic: none

Release note: none

…decoding

This hydrates the source side table descriptors with their referencing type
descriptors if they have any. This allows ldr ingestion to properly decode
tables with user defined types.

Note that LDR will still fast fail on replicating a table with user defined
types (unless the SKIP SCHEMA CHECK OPTION is used) because we still need to
teach LDR to:
- validate that the source and destination enum's are _physically_ identical
  (contain the same map from int to enum values)
- support UDT replication on sql path, which currently fails because the passed
  in datum points to the source side udt instead of the destination udt.

As another step down the line, we should relax the requirement that UDTs must
physically equivalent. Instead, they only need to be _logically_ equivalent
(i.e. have the same user facing enum values). Supporting this requires
remapping the ints from two logically equivalent enums.

Epic: none

Release note: none

This will allow us to do type descriptor validation when we check for
replicating table equivalency.

Epic: none

Release note: none