refs #16243 [fid_adlr] changes in header and main menu

* move menu items from footer to header
** mv faq and subject specialists from footer to header
** fit offset for language and registration links on mobile navigation overlay
** set nowrap for menu items to prevent line break
** raise padding for menu items
** lower font-size for menu items & screen >= lg
* fix header links
** use target blank
** use temporary links to blog
* adapt language menu to main menu
** no hover
** same line-height