I mean, let's be honest, most of these symbols are garbage candidates.
But these ones I accidentally left from trying to get ChatGPT to find
emoji for me.
More helpful were https://emojidb.org/ and http://shapecatcher.com/
I wanted to avoid duplicating tool-related state between PaintApp and
Canvas, and prepare for adding different tools with more state and which
will want to live in a separate file.
This makes it slower, when running with `textual run --dev paint.py`;
when running with `python3 paint.py`, it's fine.
When running in dev mode with `textual console` devtool connected, it's
extremely much slower. But if it was faster, you'd have more messages
to scroll through, ha. So it's a tradeoff.*
*Ideally you want it to be fast and for the logs to be compacted.
In the future, I could bypass the message system for performance, but
for now I think it's better to stay idiomatic.
- Remove scrollbar from root
- Fix extra height below color palette due to vertical layout giving even heights
- Add container around canvas to make canvas scrollable
