add background colors to the ansi command

[fdncred]

Description

This PR adds the ability to easily specific background colors using the ansi command. It also allows you to use attributes.

I also updated the grid output to be clear that the output includes an escape character, represented here by \e.

User-Facing Changes

You can see a list of these new items with ansi --list with their long and short names.

Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

• cargo fmt --all -- --check to check standard code formatting (cargo fmt --all applies these changes)
• cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A clippy::needless_collect to check that you're using the standard code style
• cargo test --workspace to check that all tests pass

After Submitting

If your PR had any user-facing changes, update the documentation after the PR is merged, if necessary. This will help us keep the docs up to date.

[sholderbach]

Yeah, that looks convenient. (although I'd struggle with all the existing shorthands)