* ui: Adds model layer required for SSO
1. oidc-provider ember-data triplet plus repo, plus addition of torii
addon
2. Make blocking queries support a Cache-Control: no-cache header
3. Tweaks to the token model layer in preparation for SSO work
* Fix up meta related Cache-Control tests
* Add tests adapter tests for URL shapes
* Reset Cache-Control to the original value, return something from logout
Adds namespace support to the UI:
1. Namespace CRUD/management
2. Show Namespace in relevant areas (intentions, upstreams)
3. Main navigation bar improvements
4. Logic/integration to interact with a new `internal/acl/authorize` endpoint