Previously, when the schema registry encountered an error when
registering a schema, it would retry the request. The problem
is that upon hitting an error, we clean the body before retrying.
Retrying with an empty body results in a obscure error
and causes the changefeed to fail. With this change, we now retry
with the original request body so the original error is sustained.

This change also adds verbose logging for the errors encountered
when registering the schema.

Release note: None
Epic: None

Release note (<category, see below>): <what> <show> <why>