rector to PHP 8.4, disable mcrypt encryption driver

[mbolli]

fixes

• many TypeErrors à la x must be of type array, null given
• add #[\Override] attributes where needed
• disable mcrypt encryption driver (mcrypt_get_iv_size(), mcrypt_encrypt() etc. got removed with PHP 7.2)

todo

• remove #[\Override] as optional and PHP 8.3 needed
• verify that ExplicitNullableParamTypeRector did not skip anything
• maybe do it again from a fresh state with the array rules disabled? there is a huge diff because arrays got reformatted

bugs

• content pages not accessible in frontend (no error, just empy pjax container)
• admin: settings mostly don't save
• admin: site/draft doesn't save and publish changes doesn't work
• admin: library collection navigation stopped being expandable:
  
  I was always using albums within albums and this is the condition to display the arrow:

  Koken-App/admin/templates/library.tmpl.html

  Line 415 in 97d3cc9

  <!-- ko if: album_type === 'set' && $data.children -->

• admin: library album view lists subalbums with a number instead of title
  

[modufolio]

@mbolli

Hi Michael, sorry for my late response, I'm recovering from a burnout. Thank you for your help. Please split this PR in 3 or multiple PR's. One for style changes like the formatting of arrays (as you suggested). Please create an PR too that only consist the needed changes to make Koken work on PHP8.4. Changes to the datamapper should always be a separate PR.