Small layout fixes

[cal0pteryx]

• Fix "more" menu button alignment in MessageToolbar (it was off vertically)
• Fix chevron direction of occupants toggle in RoomHeader (was pointing in the wrong direction)

[mremond]

Thanks !

@cal0pteryx Regarding: the direction of the occupants chevrons. It would like previously, but I switched to the current state because it felt more natural, defining the intention (expand or retract panel).
Is there a convention for that ? Not sure which to use now.

[cal0pteryx]

Hi @mremond! I actually switched the direction so that it reflects the intention (to the left to open it when it's closed; to the right to close it when it's opened) rather than the current state. But I'm not a UI expert - I just changed it to what feels natural to me :)