Avoid deleting the workspace when it's still in use.

- From now on, NSFW service disposes after last reference
is removed. No more 10sec delay.
 - Moved the temp workspace deletion to a startup task.
 - Can set initial task for the window from electron-main.
 - Removed the `browser-app`.

Closes #39

Signed-off-by: Akos Kitta <a.kitta@arduino.cc>

arduino-ide-extension/src/electron-common/startup-task.ts

@@ -0,0 +1,50 @@
+export interface StartupTask {
+  command: string;
+  /**
+   * Must be JSON serializable.
+   * See the restrictions [here](https://www.electronjs.org/docs/latest/api/web-contents#contentssendchannel-args).
+   */
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  args?: any[];
+}
+export namespace StartupTask {
+  export function is(arg: unknown): arg is StartupTask {
+    if (typeof arg === 'object') {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const object = arg as any;
+      return (
+        'command' in object &&
+        typeof object['command'] === 'string' &&
+        (!('args' in object) || Array.isArray(object['args']))
+      );
+    }
+    return false;
+  }
+  export function has(arg: unknown): arg is unknown & Owner {
+    if (typeof arg === 'object') {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const object = arg as any;
+      return (
+        'tasks' in object &&
+        Array.isArray(object['tasks']) &&
+        object['tasks'].every(is)
+      );
+    }
+    return false;
+  }
+  export namespace Messaging {
+    export const STARTUP_TASKS_SIGNAL = 'arduino/startupTasks';
+    export function APP_READY_SIGNAL(id: number): string {
+      return `arduino/appReady${id}`;
+    }
+  }
+
+  export interface Owner {
+    readonly tasks: StartupTask[];
+  }
+}
+
+export const StartupTaskProvider = Symbol('StartupTaskProvider');
+export interface StartupTaskProvider {
+  tasks(): StartupTask[];
+}