Add Dev containers for Keycloak

[akunzai]

• https://github.com/jacekkow/keycloak-protocol-cas

[gitguardian]

️✅ There are no secrets present in this pull request anymore.

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[codecov]

Codecov Report

Merging #417 (402f728) into main (567976c) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #417   +/-   ##
=======================================
  Coverage   84.83%   84.83%           
=======================================
  Files          37       37           
  Lines         890      890           
=======================================
  Hits          755      755           
  Misses        135      135