Hid the Explorer. Disabled new folder in workspace

when not in `pro-mode`.

Closes arduino/arduino-pro-ide#84.

Signed-off-by: Akos Kitta <kittaakos@typefox.io>

arduino-ide-extension/src/browser/customization/silent-navigator-contribution.ts

@@ -1,10 +1,17 @@
-import { injectable } from 'inversify';
+import { injectable, postConstruct } from 'inversify';
 import { FileNavigatorContribution } from '@theia/navigator/lib/browser/navigator-contribution';
 import { FrontendApplication } from '@theia/core/lib/browser';
 
 @injectable()
 export class SilentNavigatorContribution extends FileNavigatorContribution {
 
+    @postConstruct()
+    protected async init(): Promise<void> {
+        // @ts-ignore
+        delete this.toggleCommand; // The `Explorer` should not be accessible via command or keybinding. 
+        return super.init();
+    }
+
     async initializeLayout(app: FrontendApplication): Promise<void> {
     }