docs: fix spelling errors

- 'tirangle' -> 'triangle'
- 'cirlce' -> 'circle'
- 'gradiantSize' -> 'gradientSize'
- 'unnotied' -> 'unnoticed'
- 'consistensy' -> 'consistency'
- 'implemention' -> 'implementation'
- 'suppported/Unsuppported/suppport' -> 'supported/Unsupported/support'

modules/gapi/test/cpu/gapi_ocv_stateful_kernel_tests.cpp

@@ -575,7 +575,7 @@ TEST(StatefulKernel, StateIsResetOnceOnReshapeInStreaming)
 
     run("cv/video/768x576.avi", 1);
     // FIXME: it should be 2, not 3 for expectedSetupsCount here.
-    // With current implemention both GCPUExecutable reshape() and
+    // With current implementation both GCPUExecutable reshape() and
     // handleNewStream() call setupKernelStates()
     run("cv/video/1920x1080.avi", 3);
 }