G-API: Parameterized render tests (#14892)

* Init commit

* Add mat size as test parameter

* Add test for text render

* Add test for rect render

* Add tests for line and circle

* Remove old render tests

* Init output mats

* Remove methods input arguments

* Add comment about data loss in BGR2NV12 conversion

* Add edge test cases

* Replace default color for out mats black -> white