Implement label cheatcode

[arcz]

Description

Closes https://github.com/ethereum/hevm/issues/442.

I did a bit more work and fixed bugs in this PR too:

• There was a bug in cheatcode CallContext creation where the calldata was missing the first 4 bytes and was not displayed correctly in traces
• Unified address pretty printing
• Fixed address printing with leading @ when there is no source name / label
• Added "emit" before events, Foundry does this too
• Pretty print if bytes32 are valid string
• Changed colors a bit but I'll be revamping this anyway in a future PR. I want to turn this into prettyprinter Doc so it can be also used with Brick
• If there is any name (from source or label) don't print address unless creating
• I reformatted other cheat actions, no semantic changes there

Here is how it looks like (the code doesn't make sense, it was just for my testing):

Checklist

• [x] tested locally
• [x] added automated tests
• [x] updated the docs
• [x] updated the changelog

[msooseth]

Thanks, looks great!