Improve inserting contact to page

[JoeyStk]

Describe the Bug

After my review with @osmers we came up with a few possible improvements for inserting contacts.
This is the current implementation that we found (in 01/25):

Steps to Reproduce

1. Go on CMS Test to a page and insert a contact
2. Select any contact
3. See popup (similar as in the image)

Expected Behavior

Suggestions:

• Remove "show" / "anzeigen" from each option and instead add a headline which says "Show following information: "
• "Search for contact" should be styled differently. At the moment it's not clear by the description itself that this is a link/button and what it does
• The border shouldn't go around all of the information, just around "Search for contact"

Actual Behavior

User guidance is not clear at the moment and it's not clear what the options are and what they do.

Additional Information

Part of #2955

Related Issues

None

[JoeyStk]

Idea:
The idea was to add three headlines: One for the currently selected contact, one to switch to another contact (including the button for search contact) and below a headline for selecting the details