[Epic - Conditional Gitlab Access] @cbrown/1107 add label to namespace

[Collinbrown95]

Description

Refactor profile state controller to add the same labels added to the Kubeflow profiles to the corresponding Kubernetes namespaces.

Closes https://github.com/StatCan/daaas/issues/1107

TODO

• [x] Implement namespace label feature
• [x] Refactor handler.go so that core logic is testable
• [x] Write unit tests against core logic
• [x] Unit tests passing
• [x] Do E2E test on dev cluster (verified on dev cluster that namespaces received the same labels as profiles and that this worked for both employees and non-employees)

[saffaalvi]

LGTM!