Add a pinned message badge under a pinned message (#118)

* Add pinned message badge for Modern Layout

* Add Bubble layout support

* Add thread support

* Add irc support

* Rename event tile badges

* Don't render footer when there is no reactions

* Add a test for `PinnedMessageBadge.tsx`

* Add a test in EventTile-test.tsx

* Add e2e test

res/css/views/messages/_ReactionsRow.pcss

@@ -6,7 +6,6 @@ Please see LICENSE files in the repository root for full details.
 */
 
 .mx_ReactionsRow {
-    margin: 6px 0;
     color: var(--cpd-color-text-primary);
 
     .mx_ReactionsRow_addReactionButton {