Thanks Luke Benstead for the report Simon Charettes for the fix.

Regression in b52c7300.
Thanks Tim Graham for the review.

Refs #26709

- Fixed Oracle backend due to cx_Oracle 5.3 change in the
Cursor.description behavior i.e. "Use None instead of 0 for items in
the Cursor.description attribute that do not have any validity.".
- Used cx_Oracle.Object.size() instead of len().
Thanks Tim Graham for the review.

Using JSON as non-UTF-8 content is controversial, and the RFC 7159
discourages it.
Thanks Tim Graham for the review.

This reverts commit d895fc9a since the
test is problematic as described in the ticket.

A JSON Content-Type can contain further content, like charset for example.

This reverts commit 4cffa9a1.

Thanks Andrew Brown for the test case.

Thanks Aymeric Augustin and Carl Meyer.

Thanks Tim Graham for the review.