Ps/pm 2910/state framework improvements (#6860)

* Allow for update logic in state update callbacks

* Prefer reading updates to sending in stream

* Inform state providers when they must deserialize

* Update DefaultGlobalState to act more like DefaultUserState

* Fully Implement AbstractStorageService

* Add KeyDefinitionOptions

* Address PR feedback

* More Descriptive Error

---------

Co-authored-by: Justin Baur <19896123+justindbaur@users.noreply.github.com>

libs/common/src/platform/state/implementations/util.spec.ts

@@ -0,0 +1,50 @@
+import { FakeStorageService } from "../../../../spec/fake-storage.service";
+
+import { getStoredValue } from "./util";
+
+describe("getStoredValue", () => {
+  const key = "key";
+  const deserializedValue = { value: 1 };
+  const value = JSON.stringify(deserializedValue);
+  const deserializer = (v: string) => JSON.parse(v);
+  let storageService: FakeStorageService;
+
+  beforeEach(() => {
+    storageService = new FakeStorageService();
+  });
+
+  describe("when the storage service requires deserialization", () => {
+    beforeEach(() => {
+      storageService.internalUpdateValuesRequireDeserialization(true);
+    });
+
+    it("should deserialize", async () => {
+      storageService.save(key, value);
+
+      const result = await getStoredValue(key, storageService, deserializer);
+
+      expect(result).toEqual(deserializedValue);
+    });
+  });
+  describe("when the storage service does not require deserialization", () => {
+    beforeEach(() => {
+      storageService.internalUpdateValuesRequireDeserialization(false);
+    });
+
+    it("should not deserialize", async () => {
+      storageService.save(key, value);
+
+      const result = await getStoredValue(key, storageService, deserializer);
+
+      expect(result).toEqual(value);
+    });
+
+    it("should convert undefined to null", async () => {
+      storageService.save(key, undefined);
+
+      const result = await getStoredValue(key, storageService, deserializer);
+
+      expect(result).toEqual(null);
+    });
+  });
+});