WIP: Formatting

This fixes a number of strings and comments that are far too long that aren't formatted automatically by black, as well as adds a pyproject.toml with a default black config.

Not merging this yet since there are a number of other files that should be reformatted and because this will conflict with other ongoing work and it will likely be easier to rebase this onto other work than the other way around.

Note that I've kept the line length at 88 (black's default). While there would be some formatting benefits to a longer value such as 120 characters, this makes it easier to view files side by side.