Experimenting with optional vite integration.

[jwoertink]

Purpose

Ref #1724

Description

This is an experiment to test if we can keep mix integration while allowing for vite to be used optionally. In theory, you would just need to update your load_manifest() call to point to ./public/manifest.json, and a second use_vite: true arg. The actual setup for Vite would still need to be done, but you can use https://github.com/jwoertink/vite_lucky/ as a sort of reference.

Checklist

• - An issue already exists detailing the issue/or feature request that this PR fixes
• - All specs are formatted with crystal tool format spec src
• - Inline documentation has been added and/or updated
• - Lucky builds on docker with ./script/setup
• - All builds and specs pass on docker with ./script/test

[jwoertink]

In practice you would never run this more than once, but this was the only way I could test it since it happens at compile-time.