Aggregator: Add mutation and validation handlers (#92036)

pkg/aggregator/apiserver/plugin/fakes/plugin_context.go

@@ -0,0 +1,16 @@
+package fakes
+
+import (
+	"context"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+)
+
+type FakePluginContextProvider struct {
+	PluginContext backend.PluginContext
+	Err           error
+}
+
+func (f FakePluginContextProvider) GetPluginContext(ctx context.Context, pluginID, dsUID string) (backend.PluginContext, error) {
+	return f.PluginContext, f.Err
+}