Room list: extract getTagsForRoom from old room list store (#32716)

* refactor: extract `getTagsForRoom` from old rls

`getTagsForRoom` doesn't rely on the rls state. We can extract it safely
to an external function.

The function is not moved into the rls v3 because the rls is for the
room list and not for other ui elements.

* refactor: remove dead code

* test: add more tests for `getTagsForRoom`

* refactor: `getTagsForRoom` in old rls

* doc: add missing tsdoc for `room`

apps/web/test/unit-tests/components/views/context_menus/RoomGeneralContextMenu-test.tsx

@@ -22,13 +22,13 @@ import {
 import MatrixClientContext from "../../../../../src/contexts/MatrixClientContext";
 import { MatrixClientPeg } from "../../../../../src/MatrixClientPeg";
 import { DefaultTagID } from "../../../../../src/stores/room-list-v3/skip-list/tag";
-import RoomListStore from "../../../../../src/stores/room-list/RoomListStore";
 import DMRoomMap from "../../../../../src/utils/DMRoomMap";
 import { mkMessage, stubClient } from "../../../../test-utils/test-utils";
 import { shouldShowComponent } from "../../../../../src/customisations/helpers/UIComponents";
 import { UIComponent } from "../../../../../src/settings/UIFeature";
 import SettingsStore from "../../../../../src/settings/SettingsStore";
 import { clearAllModals } from "../../../../test-utils";
+import * as getTagsForRoomUtils from "../../../../../src/utils/room/getTagsForRoom";
 
 jest.mock("../../../../../src/customisations/helpers/UIComponents", () => ({
     shouldShowComponent: jest.fn(),
@@ -74,7 +74,7 @@ describe("RoomGeneralContextMenu", () => {
         } as unknown as DMRoomMap;
         DMRoomMap.setShared(dmRoomMap);
 
-        jest.spyOn(RoomListStore.instance, "getTagsForRoom").mockReturnValueOnce([
+        jest.spyOn(getTagsForRoomUtils, "getTagsForRoom").mockReturnValueOnce([
             DefaultTagID.DM,
             DefaultTagID.Favourite,
         ]);
@@ -87,7 +87,7 @@ describe("RoomGeneralContextMenu", () => {
     });
 
     it("renders an empty context menu for archived rooms", async () => {
-        jest.spyOn(RoomListStore.instance, "getTagsForRoom").mockReturnValueOnce([DefaultTagID.Archived]);
+        jest.spyOn(getTagsForRoomUtils, "getTagsForRoom").mockReturnValueOnce([DefaultTagID.Archived]);
 
         const { container } = getComponent({});
         expect(container).toMatchSnapshot();