ERR: re-use the err_data field when possible

ERR: re-use the err_data field when possible

To deallocate the err_data field and then allocating it again might be
a waste of processing, but may also be a source of errors when memory
is scarce.  While we normally tolerate that, the ERR sub-system is an
exception and we need to pay closer attention to how we handle memory.

This adds a new err_data flag, ERR_TXT_IGNORE, which means that even
if there is err_data memory allocated, its contents should be ignored.
Deallocation of the err_data field is much more selective, aand should
only happen when ERR_free_state() is called.

Fixes #9458

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9459)