Browser <-> desktop communication (#185)

* Add electron constant for browser integration

* Add constant for browser biometrics. Ensure biometry is locked on lock.

* Avoid saving keys outside desktop

* Fix eslint warning

* Add supportsSecureStorage helper to platformUtils to improve readability

src/abstractions/platformUtils.service.ts

@@ -34,4 +34,5 @@ export abstract class PlatformUtilsService {
     readFromClipboard: (options?: any) => Promise<string>;
     supportsBiometric: () => Promise<boolean>;
     authenticateBiometric: () => Promise<boolean>;
+    supportsSecureStorage: () => boolean;
 }