Add alwaysShowTimestamps and others to RoomView setting watchers

to allow them to update on the fly. This also modifies the setting
watchers to avoid an unnecessary settings lookup.

Signed-off-by: Robin Townsend <robin@robin.town>

src/contexts/RoomContext.ts

@@ -41,6 +41,10 @@ const RoomContext = createContext<IState>({
     canReply: false,
     layout: Layout.Group,
     lowBandwidth: false,
+    alwaysShowTimestamps: false,
+    showTwelveHourTimestamps: false,
+    readMarkerInViewThresholdMs: 3000,
+    readMarkerOutOfViewThresholdMs: 30000,
     showReadReceipts: true,
     showRedactions: true,
     showJoinLeaves: true,