feat: 🍰 Footer And Header Links Configurable To Have External Link Target

Created by: ogerly

🍰 Pullrequest

the dynamic menu for the header and footer is extended so that when an external link is entered, there is a field for the target of the link. you can therefore decide whether a new tab should be opened or not.

Issues

fixes #5545 (closed)

Sub-Branch Of

relates #5546

Todo

• refine menu
  • the hight of the header jumps between 810pxand 811px, but nothing else changes