Respect explore settings in config ini

Previous explore restrictions only took permissions into consideration.

* add `exploreEnabled` to global settings
* only bind `x` if enabled
* only show explore in panel menu if enabled

public/app/core/config.ts

@@ -16,6 +16,7 @@ class Settings {
   defaultDatasource: string;
   alertingEnabled: boolean;
   authProxyEnabled: boolean;
+  exploreEnabled: boolean;
   ldapEnabled: boolean;
   oauth: any;
   disableUserSignUp: boolean;

public/app/core/services/keybindingSrv.ts

@@ -1,6 +1,7 @@
 import $ from 'jquery';
 import _ from 'lodash';
 
+import config from 'app/core/config';
 import coreModule from 'app/core/core_module';
 import appEvents from 'app/core/app_events';
 import { encodePathComponent } from 'app/core/utils/location_util';
@@ -178,7 +179,7 @@ export class KeybindingSrv {
     });
 
     // jump to explore if permissions allow
-    if (this.contextSrv.isEditor) {
+    if (this.contextSrv.isEditor && config.exploreEnabled) {
       this.bind('x', async () => {
         if (dashboard.meta.focusPanelId) {
           const panel = dashboard.getPanelById(dashboard.meta.focusPanelId);