Prior to this commit, the `DefaultErrorWebExceptionHandler` would parse
the HTTP "Accept" headers when routing the request to the error handler;
if an error occured during parsing, an `InvalidMediaTypeException` would
be thrown and break the error handling for this request.

This commit ignores those exceptions and makes sure that the error
handling function does not override the response status or the error
itself with those exceptions.

Closes: gh-13372