PS-1133 Feature/mv3 browser observable memory caching (#3245)

* Create sessions sync structure

* Add observing to session-syncer

* Do not run syncer logic in decorator tests

* Extract test constants

* Change Observables to BehaviorSubject

* Move sendMessage to static method in BrowserApi

* Implement session sync

* only watch in manifest v3

* Use session sync on folder service

* Add array observable sync

* Bypass cache on update from message

* Create feature and dev flags for browser

* Protect development-only methods with decorator

* Improve todo comments for long-term residency

* Use class properties in init

* Do not reuse mocks

* Use json (de)serialization patterns

* Fix failing session storage in dev environment

* Split up complex EncString constructor

* Default false for decrypted session storage

* Try removing hydrate EncString method

* PR review

* PR test review

apps/browser/test.setup.ts

@@ -1,26 +1,32 @@
 // Add chrome storage api
-const get = jest.fn();
-const set = jest.fn();
-const has = jest.fn();
-const remove = jest.fn();
 const QUOTA_BYTES = 10;
-const getBytesInUse = jest.fn();
-const clear = jest.fn();
-global.chrome = {
-  storage: {
-    local: {
-      set,
-      get,
-      remove,
-      QUOTA_BYTES,
-      getBytesInUse,
-      clear,
-    },
-    session: {
-      set,
-      get,
-      has,
-      remove,
-    },
+const storage = {
+  local: {
+    set: jest.fn(),
+    get: jest.fn(),
+    remove: jest.fn(),
+    QUOTA_BYTES,
+    getBytesInUse: jest.fn(),
+    clear: jest.fn(),
   },
+  session: {
+    set: jest.fn(),
+    get: jest.fn(),
+    has: jest.fn(),
+    remove: jest.fn(),
+  },
+};
+
+const runtime = {
+  onMessage: {
+    addListener: jest.fn(),
+  },
+  sendMessage: jest.fn(),
+  getManifest: jest.fn(),
+};
+
+// set chrome
+global.chrome = {
+  storage,
+  runtime,
 } as any;