[TASK] Do not require salutation fields of addresses by default

[rintisch]

Salutation (Mr/Ms) are mostly never required to fulfill a purchase. According to GDPR companies shall collect as few data as possible. Due to this the salutation field should no longer be required by default.

Change the values of those two lines to Empty:

https://github.com/extcode/cart/blob/560a455b1f926be44092dff39350611e2e083d9d/Configuration/TypoScript/constants.typoscript#L72 https://github.com/extcode/cart/blob/560a455b1f926be44092dff39350611e2e083d9d/Configuration/TypoScript/constants.typoscript#L91

This needs a breaking change message.