Import CPP refactor from POC

[RHeckerIntel]

Initial import from POC

Contains:

1. Detection, instance segmentation, semantic segmentation
2. Support for sync, async, batch
3. Tiling support for detection

Closes #298

[sovrasov]

Thanks Ronald, impressive work. Overall, I'm ok with the changes, keeping in mind that async public API is hard to implement and it is unclear why do we need it at all. For now, I propose to delete it, and keep async features private (to emulate batch inference for instance). Now, inferAsync brings only confusion to the model interface, as not all the models and backends can support it.