Cody: Pretty much redesign everything

[SuperAuguste]

I applied most of @toolmantim's awesome Cody design ideas to the chat window with some additional things:

• I didn't get rid of the "Cody" and "Me" labels to reduce potential confusion from users + we need the edit button/feedback buttons to be displayed somewhere, and without the sender names they just look all sad and lonely :(
• I got rid of the <Header />; I love the Cody logo so much, it's equal parts cute and creepy, but it's also weird in color on dark themes and it consumes lots of much needed space, so I removed it. In my mind, we already convey that this is Sourcegraph Cody from the logo in the far-left sidebar, the name at the top, and the gray logo (which looks amazing everywhere 💅) in chat messages from Cody
• I added a chat view navigation command and icon as we need it now that we have no navbar - optimally we'll split everything out into more resizable panes later (or right now, I'm down to do this all in this PR, but I wanted to do this in chunks), but this is the best solution right now imo (except maybe adding a back button on all non-chat views, you decide :P)

Btw I have more things I want to address later, but I want to start off simpler first :)

Before

After

Test plan

Tested in VSCode and web and it looks good.

[sourcegraph-buildkite]

Bundle size report 📦

Initial size	Total size	Async size	Modules
0.00% (0.00 kb)	0.00% (+0.70 kb)	0.01% (+0.70 kb)	0.00% (0)

Look at the Statoscope report for a full comparison between the commits 9a237a8 and 0e96f9d or learn more.

Open explanation

• Initial size is the size of the initial bundle (the one that is loaded when you open the page)
• Total size is the size of the initial bundle + all the async loaded chunks
• Async size is the size of all the async loaded chunks
• Modules is the number of modules in the initial bundle

[sourcegraph-bot]

📖 Storybook live preview

[toolmantim]

Oh wow, it's super cool to see this come to life! And I like some of your changes! I'm going to check this out locally and give it all a try 👏🏼 Some of these ideas I was just in gathering feedback stage, but getting the chance to full test them out is even better. I really want to help move recipes forward into something great… this could be the start of that.

I think we'll need to keep this in draft for now? And then either cherry-pick bits alongside the work I'm doing with @abeatrix & @dominiccooney, or just troop forward with more changes on this branch and land this first. I'll check back and let you know.

[toolmantim]

@SuperAuguste thanks for hanging in while I figured out the design direction here. Let's put the recipe pane idea aside for the moment, and keep the tab bar for now.

I'd love to see these message style changes go live tho! Would it be possible to PR just that part of the change?

[SuperAuguste]

Sorry I couldn't allocate time for this, happy to see parts of it being integrated in #53332! :)