Secrets: Add v1beta1 schema with CUE + grafana-app-sdk (#107972)

* Secrets: Add v1beta1 API using CUE

* Secrets: Generate spec with app-sdk

* Secrets: Generate decrypt proto

* Secrets: Add manual files to help transition

.github/CODEOWNERS

@@ -80,6 +80,7 @@
 /apps/dashboard/ @grafana/grafana-app-platform-squad @grafana/dashboards-squad
 /apps/folder/ @grafana/grafana-app-platform-squad
 /apps/playlist/ @grafana/grafana-app-platform-squad
+/apps/secret/ @grafana/grafana-operator-experience-squad
 /apps/investigations/ @fcjack @matryer @svennergr
 /apps/advisor/ @grafana/plugins-platform-backend
 /apps/iam/ @grafana/access-squad

.github/dependabot.yml

@@ -8,6 +8,7 @@ updates:
     directories:
       - "/"
       - "/apps/playlist"
+      - "/apps/secret"
       - "/apps/investigations"
       - "/pkg/aggregator"
       - "/pkg/apimachinery"