Implement Log Masking

[4e6]

Pull Request Description

close #1720

Changelog:

• feat: add ToMaskedString interface that indicates that the object has a custom string representation masking some PII.
• feat: add --no-log-masking CLI flag that disables log masking

Important Notes

What is masked:

• Literals containing code
• Values of executed expressions
• Values of the user environment variables
• Paths inside the user project

What is not masked:

• Names of functions and modules
• Keys (names) of the user environment variables
• System and distribution paths, including a path to the user project

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the Scala, Java, and Rust style guides.
• All documentation and configuration conforms to the markdown and YAML style guides.
• All code has been tested where possible.

[iamrecursion]

Please document this whole thing in the docs. It needs to be somewhere that users can find.

Additionally, once this is merged please get a variety of people to test it and send the logs. We want to check that we've not missed masking anything important.

I also think that any component that is running with log masking disabled should warn in the console.

[iamrecursion]

Could the exception message contain sensitive data? The same question for the other exception messages we log.

[4e6]

Right, IO errors can potentially leak paths inside the user project. I'll mask them as well

[iamrecursion]

Approved, conditional on moving the logging docs into logging.md.