Switch to Vite and auto-load tools

[surma]

This PR does a couple of things:

• Switched the build process from using TypeScript CLI to Vite
• Renamed tool files to use snake_case directory structure to match the tool names
• Refactored shopifyTools to dynamically import all tool modules using Vite's import.meta.glob.
• Thanks to vite, we can now import JSON files which allows us to simplify how package.json is imported to retrieve the version.
• Move the SCHEMA_CACHE_DIR to use xdg-app-path to not rely on coincidental correctness of the data path.
• During tests, pre-populate the the cache dir with the mock schemas rather than relying on mocking node:fs.
• Remove the old mocking files.

[matteodepalo]

Code looks great! Some failures in CI but let's merge when green 👍