This adds validating admission hooks to enforce the requirements on AlertRules and RecordingRules that are currently enforced through the provisioning service and storage mechanisms in preparation of a consistent validation in both legacy storage and unified storage. It also adds a mutating admission hook to the app to ensure that folder annotations and folder labels are kept in sync so we can perform label-selector lists.
The first version of the app platform apis for alerting rules, including AlertRule and RecordingRule definitions.
Co-authored-by: William Wernert <william.wernert@grafana.com>
