feat(error): Expose error building blocks

[epage]

This has some limited programmatic use but the focus is on allowing people to format the errors as they wish.

Downside is that the .text section for the git example went from 547.9KiB to 566.8KiB. Error::formatted is the sixth largest clap function at 6.0KiB.

Fixes #2628
Fixes #3227

[ducaale]

Can you add a brief example of how users could format errors after this change? Thanks

[epage]

Can you add a brief example of how users could format errors after this change? Thanks

It might not stay this way but as of right now, this PR has clap format using context so it serves as its own example (and makes sure the data is complete enough)

clap/src/error/mod.rs

Line 687 in b965363

fn formatted(&self) -> Cow<'_, Colorizer> {