Scala 3 API & project cross compilation

[pomadchin]

• Problem: the lack of macro annotations in Scala 3
• Solution:

We can still define a macro, which would be possible to use this way ~

class NativeLoader(nativeLibrary: String):
  inline def load = ${ nativeLoaderMacro.impl('nativeLibrary) }
  load

object Adder extends NativeLoader("adder0")

It would require to have macro project as a dependency though.

Closes #45