SAML: Configuration UI (#64054)

* Add initial authentication config page skeleton

* Add initial SAML config page WIP

* Add few more pages

* Add connect to IdP page

* Assertion mappings page stub and url params

* Able to save settings

* Some tweaks for authentication page

* Tweak behaviour

* Tweak provider name

* Move SAML config pages to enterprise

* minor refactor

* Able to reset settings

* Configure key and cert from UI

* Refactor WIP

* Tweak styles

* Optional save button

* Some tweaks for the page

* Don't show info popup when save settings

* Improve key/cert validation

* Fetch provider status and display on auth page

* Add settings list to the auth page

* Show call to action card if no auth configured

* clean up

* Show authentication page only if SAML available

* Add access control for SSO config page

* Add feature toggle for auth config UI

* Add code owners for auth config page

* Auth config UI disabled by default

* Fix feature toggle check

* Apply suggestions from review

* Refactor: use forms for steps

* Clean up

* Improve authentication page loading

* Fix CTA link

* Minor tweaks

* Fix page route

* Fix formatting

* Fix generated code formatting

.github/CODEOWNERS

@@ -345,6 +345,7 @@ lerna.json @grafana/frontend-ops
 /public/app/core/components/Layers/ @grafana/dataviz-squad
 /public/app/features/all.ts @grafana/grafana-frontend-platform
 /public/app/features/admin/ @grafana/grafana-authnz-team
+/public/app/features/auth-config/ @grafana/grafana-authnz-team
 /public/app/features/annotations/ @grafana/grafana-frontend-platform
 /public/app/features/api-keys/ @grafana/grafana-frontend-platform
 /public/app/features/canvas/ @grafana/dataviz-squad