lint: Add dylint-based linting framework

[jamie-osec]

This introduces a new anchor lint command, based on dylint. This can be used with

anchor lint --path /path/to/anchor/ --pattern lints/example_lint

[vercel]

@jamie-osec is attempting to deploy a commit to the Solana Foundation Team on Vercel.

A member of the Team first needs to authorize it.

[jamie-osec]

Please note the intent here is to demonstrate some example lints; all that I'm hoping to land in this PR is the anchor lint subcommand and the diagnostic item plumbing.
In the long term, I think we can have a first-party anchor-lints repo, with security-relevant lints such as missing-account-reload living elsewhere, and the CLI configured to pull from these repos automatically.