Fix calendar events & messages fetching + fix timeline design (#11840)

Preview : 

<img width="501" alt="Screenshot 2025-05-02 at 16 24 34"
src="https://github.com/user-attachments/assets/0c649df1-0e26-4ddc-8e13-ebd78af7ec09"
/>


Done : 
- Fix getCalendarEventsFromPersonIds and getCalendarEventsFromCompanyId
(include accountOwner check)
- Fix permission check on pre-hook - Pre-hook seems useless, calendar
events are always on METADATA or SHARE_EVERYTHING visibility, else post
hook always has the responsibility of returning the data user can
access. >> To delete or to keep in case other visibility options are
added ?
- Add post hook to secure finOne / findMany calendarEvents resolver
- Update design

To do :
- same on messages (PR to arrive)

closes : https://github.com/twentyhq/twenty/issues/9826

packages/twenty-ui/src/display/avatar/components/AvatarGroup.tsx

@@ -1,5 +1,5 @@
-import { ReactNode } from 'react';
 import styled from '@emotion/styled';
+import { ReactNode } from 'react';
 
 export type AvatarGroupProps = {
   avatars: ReactNode[];
@@ -12,6 +12,10 @@ const StyledContainer = styled.div`
 
 const StyledItemContainer = styled.div`
   margin-right: -3px;
+
+  &:last-child {
+    margin-right: 0;
+  }
 `;
 
 const MAX_AVATARS_NB = 4;