Hidden Typing & Read Receipts (#2230)

* add hide activity toggle

* stop sending/receiving typing status

* send private read receipt when setting toggle is activated

* prevent showing read-receipt when feature toggle in on

src/app/features/room/RoomViewFollowing.css.ts

@@ -1,6 +1,14 @@
+import { style } from '@vanilla-extract/css';
 import { recipe } from '@vanilla-extract/recipes';
 import { DefaultReset, color, config, toRem } from 'folds';
 
+export const RoomViewFollowingPlaceholder = style([
+  DefaultReset,
+  {
+    height: toRem(28),
+  },
+]);
+
 export const RoomViewFollowing = recipe({
   base: [
     DefaultReset,