Pinned feeds cards (#4526)

* Add lists support to FeedCard

* Add useSavedFeeds query, similar to usePinnedFeedInfos

* Integrate into Feeds screen

* Fix alignment on mobile

* Update usages

* Add placeholder loading state

* Handle no feeds state

* Reuse previous data for placeholder

* Staged loading

* Improve staged loading

* Use setQueryData approach to pre-caching

* Add types for a little more safety

* Fix precaching

---------

Co-authored-by: Dan Abramov <dan.abramov@gmail.com>

src/view/screens/Search/Explore.tsx

@@ -505,7 +505,7 @@ export function Explore() {
                 a.px_lg,
                 a.py_lg,
               ]}>
-              <FeedCard.Default feed={item.feed} />
+              <FeedCard.Default type="feed" view={item.feed} />
             </View>
           )
         }

src/view/screens/Search/Search.tsx

@@ -306,7 +306,7 @@ let SearchScreenFeedsResults = ({
                 a.px_lg,
                 a.py_lg,
               ]}>
-              <FeedCard.Default feed={item} />
+              <FeedCard.Default type="feed" view={item} />
             </View>
           )}
           keyExtractor={item => item.uri}