POC timeline activity (#5697)

TODO: 
- remove WorkspaceIsNotAuditLogged decorators on activity/activityTarget
to log task/note creations
- handle attachments
-  fix css and remove unnecessary styled components or duplicates

packages/twenty-front/src/modules/activities/emails/components/EmailThreadHeader.tsx

@@ -44,9 +44,11 @@ export const EmailThreadHeader = ({
     <StyledContainer>
       <StyledHead>
         <StyledHeading>{subject}</StyledHeading>
-        <StyledContent>
-          Last message {beautifyPastDateRelativeToNow(lastMessageSentAt)}
-        </StyledContent>
+        {lastMessageSentAt && (
+          <StyledContent>
+            Last message {beautifyPastDateRelativeToNow(lastMessageSentAt)}
+          </StyledContent>
+        )}
       </StyledHead>
     </StyledContainer>
   );