Grafana Indexing PoC: Adds feature flag and gRPC endpoint (#93356)

* adds Filter gRPC and make protobuf

* adds route for querying the filter gRPC

* wires up Filter gRPC call

* [WIP] index from start

* renames gRPC endpoint to "Search"

* adds /apis/search route into k8s routes. Hacky for now.

* updates readme - wrong casing

* adds feature toggle for unified storage search

* hides US search behind feature flag. Clean up print statements.

* removes indexer - will be added in another PR

* Search: Add API Builder

* adds required method

* implementing UpdateAPIGroupInfo (WIP)

* adds groupversion

* commenting out for now

* remove unneeded code from experimenting and update register.go to match interface required

* namespaces search route

---------

Co-authored-by: leonorfmartins <leonorfmartins@gmail.com>
Co-authored-by: Todd Treece <todd.treece@grafana.com>

pkg/registry/apis/wireset.go

@@ -14,6 +14,7 @@ import (
 	"github.com/grafana/grafana/pkg/registry/apis/playlist"
 	"github.com/grafana/grafana/pkg/registry/apis/query"
 	"github.com/grafana/grafana/pkg/registry/apis/scope"
+	"github.com/grafana/grafana/pkg/registry/apis/search"
 	"github.com/grafana/grafana/pkg/registry/apis/service"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/plugincontext"
 )
@@ -40,4 +41,5 @@ var WireSet = wire.NewSet(
 	scope.RegisterAPIService,
 	notifications.RegisterAPIService,
 	//sso.RegisterAPIService,
+	search.RegisterAPIService,
 )