[TASK] Add labels for gender

[rintisch]

Provide labels for gender which makes it
easier for integrators to set up
radio buttons for the salutation instead
of using the default text input field.

With these labels in place a tutorial can
be added to the documentation how
integrators can replace the default input
field with radio buttons. Furthermore another
step could be to add an opt-in solution to
switch to radio button for the addresses.

[rintisch]

@extcode I used e.g. tx_cart_domain_model_order_address.gender.female instead of tx_cart_domain_model_order_address.salutation.female for the keys (means: gender instead of salutation).
I had the feeling it's more logical but on the other side it's less homogenous / less strict.
What do you prefer?

[extcode]

I would hate to include that. The same applies here as for the salutation field. In my opinion, such a field is not required as standard for an order. I would like to remove both fields for TYPO3 v13 and document a way to make these fields available again.
There may be exceptional cases where it might be relevant to know the gender, but this is more relevant for a product (event registration) than for the billing address.

[rintisch]

I really don't want you to merge something that you dislike that hard! I like your privacy first thinking. Just think these labels would be good for the coming documentation that you named as well?
BTW: As a result I will remove the salutations field in my coming project as well because you are right, it is not needed. Added it more as a habit. And it might even improve conversion rates as customer has to fill less fields=less thinking.