[epage]

What does this PR try to resolve?

This is a follow up to #12245 which is working to resolve the tracking issue #12207

This first aligns sanitization of package names with the central package name validation logic, putting the code next to each other so they can more easily stay in sync.

Oddly enough, cargo-new is stricter than our normal package-name validation. I went ahead and sanitized along with that as well.

In working on this, I was bothered by

• the mix of - and _ in file names because of sanitization, so I made it more consistent by detecting which the user is using
• -using _ in bins, so I switched the default to -

How should we test and review this PR?

One existing test covers a variety of sanitization needs

Another existing test hit one of the other cases (test being reserved)

Additional information

For implementation convenience, I changed the directory we write the manifest to. The impact of this should be minimal since

• We reuse the full file name, so if it worked for the user it should work for us
• We should be moving away from the temp manifest in future commits