introduce `MessageReactionsModal`. `MessageReactionsModal` shows all the users who have reacted to a message, what their username is and what reaction they used. I decided to punt the implementation of the filter buttons at the top of the design since every message will be a like for the moment
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Depends on D6348
Linear Task: [[ https://linear.app/comm/issue/ENG-2719/add-reaction-list-modal-on-native | ENG-2719 ]]