Add a reusable raytracing API

## What problem does this solve or what need does it fill?

A lack of use case expression for ray tracing, such as audio raytracing, potentially fluid simulation, and other unorthodox methods that it may be used for.

## What solution would you like?

Divide solari into a raytracing frontend, and have solari use that.

## What alternative(s) have you considered?
using solari's implementation directly, as a lot of it is bevy code.

Start by reading Solari's existing ray-tracing implementation and identifying the Bevy-specific parts it currently uses. The issue names no files or tests; clarify the reusable frontend boundary and supported use cases before implementation, with the API separation and its validation defining done.

Written by the indexing model from the issue text.