Add register_taxonomy_args filter

[johnbillion]

Follow-up to #17447.

A corresponding filter should be added for the args when registering a taxonomy.

[tyxla]

Introducing a register_taxonomy_args filter that allows to modify the $args when registering a taxonomy.

[johnbillion]

In 34787:

Introduce a register_taxonomy_args filter for filtering the arguments passed when calling register_taxonomy(). This is the taxonomy equivalent of the newly introduced register_post_type_args filter.

Fixes #33990
Props tyxla for initial patch

[johnbillion]

#14449 was marked as a duplicate.