[7.11.24] Create form for contacts

[MizukiTemma]

Motivation

We are introducing a new feature "contact information". A form is needed for it.

Proposed Solution

Implement a form to create a new contact and to edit an existing one.

❓ Make it sure at least one of E-mail address, telephone number or website is given. 💡 Reuse venue_box.html for the step of selecting/creating a POI. 💡 Reuse _related_contents_table.html to show where the contact is embedded.

Alternatives

None. We do it.

User Story

Additional Context

Wait for #2952

Design Requirements

See the design here ⚠️ There are two versions in the link above. New Version 30.07 is the one we have to implement.

[MizukiTemma]

The cancel (Abbrechen) button will be implemented in #2930. It is not consistent with other contents and may be confusing for users if the cancel button is only available in the contact form.

[MizukiTemma]

blocked by #3015

[MizukiTemma]

The design suggests to mark the fields "title" and "name" with to make it clear that they are mandatory, but mandatory fields of other forms are not marked at all. Should we probably introduce the `` systemwide at once, to avoid inconsistency and confusion? #3028

[MizukiTemma]

TBD: removing E-mail, phone number and website from POI.

We have those three fields not only in POIs but also in contacts. If those fields are managed only in contacts, we can avoid redundancy, maintenance like #3033 and check boxes in #3034 .

@david-venhoff Feel free to add commnets 😸 @PeterNerlich You're invited to the discussion too 😸