G-API: Render (#14700)

* cv::Render

Implement OCVRedner for BGR as input

* Support two plane cv::Render::run

* Snapshot

* Add RenderCreator

* text2Points

* Snapshot

* Refactoring tests

* Remove text2points

* Fix render input data type in tests

* Refactoring

* Fix headers
* Change struct fields name

* Fix headers

* Fix warnings

* Replace cv::Scalar -> cv::gapi::own::Scalar

* Add test

* PutText and rectangle case

* Fix comments to review

* Fix comments to review

* Fix comments to review

* Create render_priv.hpp
* Implement BGR2NV12
* Fix NV12 test

* Fix comments to review

* Add header for GAPI_Assert