Bevy integration

[norman784]

[norman784]

It kinda works, but there's an artifact with the texture, maybe isn't related to bevy, but with how the mesh duplicates the vertices, because I have almost the same issue in blender with the generated meshes (see https://github.com/norman784/gaiku/issues/27#issuecomment-761829133)

[norman784]

Need to figure out how to by pass the issue when compiling amethyst and bevy examples, seems that there is a conflict with the dependencies. See the log below for more details

error: multiple packages link to native library `alsa`, but a native library can be linked only once

package `alsa-sys v0.1.2`
    ... which is depended on by `cpal v0.11.0`
    ... which is depended on by `amethyst_audio v0.15.3`
    ... which is depended on by `amethyst v0.15.3`
    ... which is depended on by `gaiku-amethyst v0.1.0 (/home/runner/work/gaiku/gaiku/gaiku-amethyst)`
links to native library `alsa`

package `alsa-sys v0.3.1`
    ... which is depended on by `alsa v0.4.3`
    ... which is depended on by `cpal v0.13.1`
    ... which is depended on by `rodio v0.13.0`
    ... which is depended on by `bevy_audio v0.4.0`
    ... which is depended on by `bevy_internal v0.4.0`
    ... which is depended on by `bevy v0.4.0`
    ... which is depended on by `gaiku-bevy v0.1.0 (/home/runner/work/gaiku/gaiku/gaiku-bevy)`
also links to native library `alsa`

[QuantumEntangledAndy]

Need to figure out how to by pass the issue when compiling amethyst and bevy examples

Currently the github build script builds from the workspace level. We could instead for loop and cd into each subspace and build there. That would treat them as isolated. But if a new subspaces is added we'd need to add it the the loop in the github build script

[norman784]

Maybe we should remove from the workspace the game engine integrations crates but still leave them in the current repo. Also if we do this we should group the agnostic crates (common and 3d) into a folder crates and the game engine integrations into the integrations folder.