NIEDUUI-235: Move the conferences part for the current affairs panel to the dev branch

[maierdominik]

JIRA: https://schulz-informatik.atlassian.net/browse/NIEDUUI-235

NIEDUUI-235:

• CurrentAffairs: move the part for the conferences from dev-preview in dev

Additionally

• replaced some background colors:
  • bg-red-400 & bg-red-500 -> bg-ciLightRed
  • bg-red-600 & bg-red-700 -> bg-ciRed