G-API: Extend MediaFrame to be able to extract additional info besides access
* Extend MediaFrame to be able to extract additional info besides access
* Add default implementation for blobParams()
* Add comment on the default blobParams()
* G-API: Make GFrame a new (distinct) G-type, not an alias to GMat
- The underlying host type is still cv::Mat, a new cv::MediaFrame
type is to be added as a separate PR
* Fix warnings and review comments
- Somewhow there was a switch() without a default: clause in Fluid