Thread muting [APP-29] (#500)

* Implement thread muting

* Apply filtering on background fetched notifs

* Implement thread-muting tests

src/view/com/notifications/Feed.tsx

@@ -135,8 +135,9 @@ export const Feed = observer(function Feed({
           />
         )}
       </CenteredView>
-      {data.length && (
+      {data.length ? (
         <FlatList
+          testID="notifsFeed"
           ref={scrollElRef}
           data={data}
           keyExtractor={item => item._reactKey}
@@ -155,7 +156,7 @@ export const Feed = observer(function Feed({
           onScroll={onScroll}
           contentContainerStyle={s.contentContainer}
         />
-      )}
+      ) : null}
     </View>
   )
 })

src/view/com/notifications/FeedItem.tsx

@@ -85,7 +85,11 @@ export const FeedItem = observer(function FeedItem({
       return <View />
     }
     return (
-      <Link href={itemHref} title={itemTitle} noFeedback>
+      <Link
+        testID={`feedItem-by-${item.author.handle}`}
+        href={itemHref}
+        title={itemTitle}
+        noFeedback>
         <Post
           uri={item.uri}
           initView={item.additionalPost}
@@ -147,6 +151,7 @@ export const FeedItem = observer(function FeedItem({
 
   return (
     <Link
+      testID={`feedItem-by-${item.author.handle}`}
       style={[
         styles.outer,
         pal.view,