Spike: Replace Laravel Mix with Vite

[eteubert]

We use Laravel Mix to bundle the legacy js in the js directory. However, that project is abandoned. And there is security issue in a sub dependency (webpack) that needs to be fixed. The quick fix would be to bump webpack in the lock file, but eventually we need to get rid of it. This is the exploration.

Lots of weirdness in the legacy code:

• some dependencies were copied in the source tree instead of an npm dep
• some of the code is dead, but figuring out what can be removed is for another day (except some very obvious cases)
• very strange JS module code in combination with var PODLOVE = PODLOVE || {}; as a global space hack.

Eventually all of this should move and/or be rewritten to the new codebase. But let's see how far I get with duct tape before we start another months-long transitioning journey.