AsyncInjector: do we need it? Consider switching to Koin

[soywiz]

AsyncInjector might have been useful for some use-cases. But in practice, it is most of the time not used. When this was started there was not an option, and I also needed to have control on all the targets I was generating. Now that Koin is stablished, we can investigate deprecating korinject and use Koin.

We will need WASM and other targets to be supported to enable all the targets we want to support. So let's investigate and make a talk about this with them.