[dmt] Fix rbac.placement errors

[RottenRat]

Fixed logic of rbac.placement linter
Errors are now more understandable in more cases

Example:

🐒 [placement (#rbac)]
     Message:      Service account namespace should be equal to "d8-monitoring" namespace
     Module:       extended-monitoring
     Object:       kind = ServiceAccount ; name = image-availability-exporter ; namespace = d8-test
     FilePath:     templates/image-availability-exporter/rbac-for-us.yaml