feat: Add CommonJS module to build output

[louis-pre]

Context

Working on SPF (standard provider fakes), we need to import edgespec in seam-connect which is a CommonJS project. Unfortunately, edgespec's build is currently ES only which means it can not be imported synchronously from a CJS project. Importing it asynchronously is not a good option here as it causes other issues down the line.

This partially reverts https://github.com/seamapi/edgespec/pull/138

Changes

• Add a new CJS build output using tsup
• Reorder subpath conditional exports (types above the other conditions, see https://nodejs.org/api/packages.html#community-conditions-definitions)

! Risk

The original PR by Max was to resolve some kind of type issue but I could not reproduce it myself

[louis-pre]

Moved back to draft as I am still having issues