Think about how to maintain liboni in this repo

[jonnew]

Right now, it looks like there are manually copied header files along with pre-build dynamic libraries. We probably want to think of a more automated and standardized way to bring these dependencies in. Perhaps this is really an issue for the liboni repo to get automated builds and package management going over there so those artifacts can be referenced by dependent projects, like this one.

[jonnew]

To solve this, we simply need to get rid of the libONI folder and replace it with liboni submodule. The core liboni csproj inside that repo can be added to this plugin's cmake thing.