Dynamic Modals (#417)

* Move backdrop and click handler to modal service since they should not be used in web

* Add support for opening modals using ViewContainerRef

electron/src/services/electronPlatformUtils.service.ts

@@ -151,11 +151,6 @@ export class ElectronPlatformUtilsService implements PlatformUtilsService {
         return Promise.resolve(result.response === 0);
     }
 
-    async showPasswordDialog(title: string, body: string, passwordValidation: (value: string) => Promise<boolean>):
-        Promise<boolean> {
-        throw new Error('Not implemented.');
-    }
-
     isDev(): boolean {
         return isDev();
     }