[BUG]: UI Issues

[ericrallen]

A number of UI issues discovered during the refactor and upgrade to v2:

1. Memory state selector needs to be absolutely positioned and able to flow outside of the container so that it doesn't cause the conversation view to jump around
2. Conversation Settings dropdowns need to be realigned - model dropdown gets cut off
3. Need horizontal space between stop button and loading indicator - make stop button more apparent
4. Are user handle and bot handle still useful? If so, default to a non-ChatGPT one