Asynchronous resource loading

[igordmn]

Android supports asynchronous loading:

@Composable
fun loadFontResource(...): DeferredResource<Typeface>

@Composable
fun loadVectorResource(...): DeferredResource<VectorAsset>

@Composable
fun loadImageResource(...): DeferredResource<ImageAsset>

We need to implement it on desktop too (and also move some of the classes to commonMain)

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.