chore: Upgraded keycloak version and dependencies

[dcostersabin]

Changes

1. Upgraded configuration source and target to 17 and keycloak version to 26.1.0
2. Modified imports since keycloak moved to jakarta
3. Removed no cache and set the method to POST so that it wont cache automatically
4. Modified compose file to use latest and official keycloak image as of now (26.1.0)
5. Modified compose file to use latest postgres image as of now (17.2)
6. Modified dest-app and start-app urls to match latest keycloak url pattern