Templating: removes old Angular variable system and featureToggle (#24779)

* Chore: initial commit

* Tests: fixes MetricsQueryEditor.test.tsx

* Tests: fixes cloudwatch/specs/datasource.test.ts

* Tests: fixes stackdriver/specs/datasource.test.ts

* Tests: remove refrences to CustomVariable

* Refactor: moves DefaultVariableQueryEditor

* Refactor: moves utils

* Refactor: moves types

* Refactor: removes variableSrv

* Refactor: removes feature toggle newVariables

* Refactor: removes valueSelectDropDown

* Chore: removes GeneralTabCtrl

* Chore: migrates RowOptions

* Refactor: adds RowOptionsButton

* Refactor: makes the interface more explicit

* Refactor: small changes

* Refactor: changed type as it can be any variable type

* Tests: fixes broken test

* Refactor: changes after PR comments

* Refactor: adds loading state and call to onChange in componentDidMount

packages/grafana-data/src/types/config.ts

@@ -38,7 +38,6 @@ export interface FeatureToggles {
    * Available only in Grafana Enterprise
    */
   meta: boolean;
-  newVariables: boolean;
 }
 
 /**

packages/grafana-e2e/cypress/fixtures/example.json

@@ -0,0 +1,5 @@
+{
+  "name": "Using fixtures to represent data",
+  "email": "hello@cypress.io",
+  "body": "Fixtures are a great way to mock data for responses to routes"
+}

packages/grafana-runtime/src/config.ts

@@ -1,14 +1,14 @@
 import merge from 'lodash/merge';
 import { getTheme } from '@grafana/ui';
 import {
+  BuildInfo,
   DataSourceInstanceSettings,
+  FeatureToggles,
+  GrafanaConfig,
   GrafanaTheme,
   GrafanaThemeType,
-  PanelPluginMeta,
-  GrafanaConfig,
   LicenseInfo,
-  BuildInfo,
-  FeatureToggles,
+  PanelPluginMeta,
 } from '@grafana/data';
 
 export class GrafanaBootConfig implements GrafanaConfig {
@@ -52,7 +52,6 @@ export class GrafanaBootConfig implements GrafanaConfig {
     expressions: false,
     newEdit: false,
     meta: false,
-    newVariables: true,
   };
   licenseInfo: LicenseInfo = {} as LicenseInfo;
   rendererAvailable = false;