This makes the popups in the plugin (those for editing and creating comments, replies, the pipeline, etc) configurable. Users can change the default width, height, transparency, and border properties, and set overrides per popup.
This MR adds the ability to sort discussions by file name, rather than just by date.
This is an optional configuration that can be passed in on startup. The MR also introduces a test suite for the Lua code that runs through Neovim, so that the plugin can be fully tested with required dependencies and APIs.
Major props to @johnybx for the hard work on this change!
