clean up dynamic plugin loading

Summary:
There are 3 sources where plugins can be loaded from:
* `src/plugins`
* `src/fb/plugins`
* any path specified in `~/.sonar/config.json`

Plugins found in the first two directories are bundled with the app when building.

Reviewed By: jknoxville

Differential Revision: D8636061

fbshipit-source-id: 2064090d43d11695ffd99df195e5b594559fe087

src/MenuBar.js

@@ -8,11 +8,6 @@
 import type {SonarBasePlugin} from './plugin.js';
 
 import {devicePlugins} from './device-plugins/index.js';
-import {
-  isProduction,
-  loadsDynamicPlugins,
-  toggleDynamicPluginLoading,
-} from './utils/dynamicPluginLoading.js';
 import plugins from './plugins/index.js';
 import electron from 'electron';
 
@@ -332,15 +327,6 @@ function getTemplate(app: Object, shell: Object): Array<MenuItem> {
         {
           type: 'separator',
         },
-        {
-          label: `Restart in ${
-            loadsDynamicPlugins() ? 'Production' : 'Development'
-          } Mode`,
-          enabled: isProduction(),
-          click: function() {
-            toggleDynamicPluginLoading();
-          },
-        },
         {
           label: 'Quit',
           accelerator: 'Command+Q',