Plugins: converted the plugins admin app to a core feature in grafana (#36026)

* moved the plugins admin to core and used the plugins toggle to decide which version to use.

* reverted change.

* changed so the library tab is the default one.

* fixing navigation.
#

* fixed so we have the proper header.

* including the core plugins

* fixed so we display logos for local plugins.

* fixed so we have a working version of plugin catalog.

* removed console logs.

* reverted changes.

* fixing failed test.

pkg/plugins/manager/manager_test.go

@@ -40,7 +40,7 @@ func TestPluginManager_Init(t *testing.T) {
 
 		assert.Empty(t, pm.scanningErrors)
 		verifyCorePluginCatalogue(t, pm)
-		verifyBundledPluginCatalogue(t, pm)
+		verifyBundledPlugins(t, pm)
 	})
 
 	t.Run("Base case with single external plugin", func(t *testing.T) {
@@ -607,12 +607,11 @@ func verifyCorePluginCatalogue(t *testing.T, pm *PluginManager) {
 	}
 }
 
-func verifyBundledPluginCatalogue(t *testing.T, pm *PluginManager) {
+func verifyBundledPlugins(t *testing.T, pm *PluginManager) {
 	t.Helper()
 
 	bundledPlugins := map[string]string{
-		"input":                    "input-datasource",
-		"grafana-plugin-admin-app": "plugin-admin-app",
+		"input": "input-datasource",
 	}
 
 	for pluginID, pluginDir := range bundledPlugins {
@@ -625,7 +624,6 @@ func verifyBundledPluginCatalogue(t *testing.T, pm *PluginManager) {
 	}
 
 	assert.NotNil(t, pm.dataSources["input"])
-	assert.NotNil(t, pm.apps["grafana-plugin-admin-app"])
 }
 
 type fakeBackendPluginManager struct {