1672: Improve birthday field

[f1sh1918]

Short description

As a koblenz pass applicant i want to provide my birthday easily on a mobile device

Proposed changes

• added a custom mui datepicker in desktop variant that enables date input with (virtual) keyboard
• improved datepicker usage by choosing date -> month -> day on calendar icon click and dropdown
• add error hint
• adjusted the clearButton slightly to fit better to material icons

Note

• it makes sense to reuse this component for other date inputs to unify behavior and especially for the application process for bavaria we should reuse this approach even the styling is a bit different Unify Datepicker components #1766
• the style for the calendar differs to the design, since its a lot of effort to customize that and i think not worth the effort
• the under 16 years old check is not really clear. I don't think this makes sense because no one can create a card for their children if we disallow that.

Side effects

• none

Testing

1. Please start the application on a real mobile device to check if everything works fine
2. Create a card and activate it and check if birthday value is correct

Resolved issues

Fixes: #1672

[steffenkleinle]

Tested on firefox, works great 🎉

[ztefanie]

(minor)
Currently the styling of the DateField and the other Text fields in same, when not selected, but different when selected:

[ztefanie]

Would it be possible to move this color to a constant in the colors file for reuse? I understand that a separate cleanup task is planned for moving existing colors, but keeping new feature colors organized in the central file now could save us time in the future. That way, we won’t need to revisit this feature when we tackle that cleanup, and it will keep everything tidy as we go. Thank you!

[f1sh1918]

(minor) Currently the styling of the DateField and the other Text fields in same, when not selected, but different when selected:

I think this issue will be solved with #1779 and is as you said really minor.
To manually override the style now is really ugly and difficult to find. You can give it a try, i already spend couple of hours on that