Integrate rafx-plugin codegen into the rafx-plugin crate. This allows us to remove the rafx-plugins-shaders crate and publish a single crate without also needing to publish a separate codegen crate.
The old style of having codegen in a separate crate is still supported and recommended for end-users. For plugins that are to be published, integrating codegen into the plugin crate is cleaner for publishing.
Integrate rafx-plugin codegen into the rafx-plugin crate. This allows us to remove the rafx-plugins-shaders crate and publish a single crate without also needing to publish a separate codegen crate.
The old style of having codegen in a separate crate is still supported and recommended for end-users. For plugins that are to be published, integrating codegen into the plugin crate is cleaner for publishing.