Plugins: Migrate PluginStore mock to pre-existing fakes package (#71664)

* migrate to existing fakes package

* fix imports

pkg/expr/dataplane_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/infra/tracing"
 	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/manager/fakes"
 	"github.com/grafana/grafana/pkg/services/datasources"
 	datafakes "github.com/grafana/grafana/pkg/services/datasources/fakes"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
@@ -52,7 +53,7 @@ func framesPassThroughService(t *testing.T, frames data.Frames) (data.Frames, er
 		cfg:         cfg,
 		dataService: me,
 		features:    &featuremgmt.FeatureManager{},
-		pCtxProvider: plugincontext.ProvideService(nil, &plugins.FakePluginStore{
+		pCtxProvider: plugincontext.ProvideService(nil, &fakes.FakePluginStore{
 			PluginList: []plugins.PluginDTO{
 				{JSONData: plugins.JSONData{ID: "test"}},
 			}},