Migration to Bevy 0.12

[bilowik]

Currently blocked by an issue with the embedded_asset! macro, see bevyengine/bevy#10377
Could just rework the existing load_internet_asset! macro usage with the changes to UntypedHandle but is probably best to wait on 0.12.1. Alternatively, could probably take a look at the expanded macro and make the necessary adjustments for the pathing and hardcode for now.

[bilowik]

I apologize I didn't realize this would show up in that PR.. I thought issue mentions were typically within repository bounds... I didn't mean to gunk up an issue tracker with a silly hobby project. I just wanted to keep tabs on it for when I round back to it in the future.

[bilowik]

Decided to look at the expanded macro, was pretty straightforward to make the calls directly and set up the expected path, so went with that. May round back later to rewrite it to utilize the embedded_asset! macro if the fix makes it into 0.12.1.

[bilowik]

Last thing to note, hot reloading will probably not work with the above fix, not that it is needed but if somehow someone happens upon this and tries to make changes and wonders why when they enable the hotreloading feature for embedded assets and it does not work for the shader, this is why.