Improved `deno info --json` output for `npm:` and `node:` modules

[lucacasonato]

Right now the representation of npm: specifiers in deno info --json are inconsistent. For example, npm: specifiers are currently added as an entry to the "modules" array if they are a root module, but are not added if they are a dependency of a "standard" (https: or file: module). There are entries in the redirects for NPM modules, but they point to specifiers that are only visible through the deps array on modules. Long story short, dealing with NPM specifiers in deno info --json is a royal PITA right now and requires many special cases. It also breaks backwards compat with the expectation that all RHS of the redirects map have entries in the modules array.

I propose we fix this as follows:

• each final resolution of a given NPM module + subpath is added as an entry in the modules array
• the pointer for npm: module -> package info in npmPackages is per module in the modules array, not per import in the deps array
• deps array is identical regardless of what kind of module the import points to
• each module can be either of kind esm, npm or node
  • all three kinds have the specifier field
  • all three kinds can optionally have the error field
  • npm packages have the npmPackage field, and additionally a seperate field for subpath
  • esm kind stays as is
  • node kind has a field that stores the encoded path (eg node:fs/promises would have fs/promises in this field)
• redirects are used to map npm:preact to npm:preact@10.13.0

[dsherret]

For this, we'll do the current output by default, but print a warning to provide --format=json.1 flag. Then we'll upgrade --format=json.2 to do this output. We should move this out of deno graph and do serialization from a ModuleGraph that doesn't just call graph.serialize(...) so the format can be more stable.