Added intention for replacing explicit iteration with delegation to sub-generator for Python 3.3 (PY-7383)

python/testData/intentions/afterYieldFrom.py

@@ -0,0 +1,4 @@
+def f(g):
+    yield 'begin'
+    yield from g()
+    print('end')

python/testData/intentions/beforeYieldFrom.py

@@ -0,0 +1,5 @@
+def f(g):
+    yield 'begin'
+    for x in g():
+        yield <caret>x
+    print('end')