**PLEASE NOTE THAT THIS DIFF AND SUBSEQUENT DIFFS IN THIS STACK WILL NOT BE LANDED UNTIL MORE OF THE REDESIGN IS READY SINCE THIS WILL CAUSE REGRESSIONS IN PROD**
This diff updates the chat input bar + any extra relevant elements as part of the chat input bar (join chat button, image previews, and explanations). In this diff I did the following:
- I added a border top drop shadow inset to the join chat button and to the multimedia previews container, and explanation container
- I added a border top drop shadow inset to the chat input bar and removed any top padding
- I moved the multimedia button to be housed within the chat input bar
Here are some figma screenshots that show the different edge cases:
{F1043591}
{F1043590}
Linear task: https://linear.app/comm/issue/ENG-5971/update-the-chat-input-field-ui and https://linear.app/comm/issue/ENG-5972/update-the-join-chat-button-ui
Depends on D10565