fix(tests): Ensure ldap server can be reached in integration tests on GitHub Actions...

fix(tests): Ensure ldap server can be reached in integration tests on GitHub Actions and other improvments

* Run integration tests for every pull request
* Also print docker logs of service containers (ldap, redis)
* Ensure consistent `datadir` for test assertions
* Test openldap features separatly
* Only the LDAP tests rely on `/dev/shm` while `federated.feature` rely on real directory access

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>