Finish implementation of `versionsuffix` and `cm-canon-names`

[alexcrichton]

I started some work in #2555, but there is remaining work to do. Notably:

• Right now it's validated that the suffix and prefix together make a complete semver, but the exact split point shoudl be subject to some sort of validation rule. I think this is something where the upstream spec will need to be consulted and kept in sync.
• Right now the validation I implemented, that the prefix/suffix combo is required to be a valid semver, is technically more restrictive than the upstream spec. This probably wants to be sync'd.
• There's no integration with wit-component right now, meaning you cannot create a component that uses versionsuffix.
• There's no way to have a core wasm module import from wasi:filesystem/types@0.3, for example, and get that integrated into wit-component.
• Emission of versionsuffix in wit-component will want to be conditional to start while runtimes catch up. There'll need to be some switch to say "yes do the thing" where without the switch full semver versions are emitted.
• The version-matching algorithms in wit-parser and wit-component will want to get tweaked to handle this new form of imports. Or, rather, I assume that something about them will want some handling.