Remove old fields when transforming api request

If the old 'firstname' and 'lastname' fields exist in the request after
the transformation wrapper the request handling fails with "unknown
field" errors. The goal of the transformation is to make v2 API requests
indistinguishable from v3 API requests, so it makes sense to remove the
now invalid keys from the request dict.
Merge pull request #1430 from jwalgran/hotfix/smushname

Remove old fields when transforming api request
Send id fields when serializing collection UDFs

This allows the backend to determine if a row is new or already present,
and prevents it from generating spurious audit logs for unchanged rows
which are already present.

Fixes #1327
Merge pull request #1431 from maurizi/fix/1327/cudf-audit-logs

Send id fields when serializing collection UDFs
Merge branch 'release'