Setup pin/unpin actions and mark messages pinned in timeline

ts/components/conversation/Timeline.dom.stories.tsx

@@ -55,6 +55,7 @@ function mockMessageTimelineItem(
       canEditMessage: true,
       canEndPoll: false,
       canForward: true,
+      canPinMessages: true,
       canReact: true,
       canReply: true,
       canRetry: true,
@@ -67,6 +68,7 @@ function mockMessageTimelineItem(
       text: 'Hello there from the new world!',
       isBlocked: false,
       isMessageRequestAccepted: true,
+      isPinned: false,
       isSelected: false,
       isSelectMode: false,
       isSMS: false,
@@ -312,6 +314,8 @@ const actions = () => ({
   doubleCheckMissingQuoteReference: action('doubleCheckMissingQuoteReference'),
 
   openGiftBadge: action('openGiftBadge'),
+  onPinnedMessageAdd: action('onPinnedMessageAdd'),
+  onPinnedMessageRemove: action('onPinnedMessageRemove'),
   scrollToPinnedMessage: action('scrollToPinnedMessage'),
   scrollToPollMessage: action('scrollToPollMessage'),
   scrollToQuotedMessage: action('scrollToQuotedMessage'),