Fix test data in several tests that failed after PyUtil#deleteElementSafely was introduces

* `pass` is consistently inserted on the new line now
* excess spaces left after element was deleted are removed

Use PyUtil#deleteElementSafely in pull, push and extract superclass
refactoring implementations.

It turned out that all problems with whitespaces left after we moved
function are rooted in awkward implementation of PyFunctionImpl#delete()
that delegated to plain AST manipulation and thus ignored
usual additional reformatting step. I removed it and it's allowed to
clean a lot of test files and remove the code that was added previously
exactly for this purpose in PyMoveSymbolProcessor.

python/testData/refactoring/move/importSlash/after/src/file1.py

@@ -3,4 +3,3 @@ __author__ = 'catherine'
 def function_1():
     pass
 
-

python/testData/refactoring/move/moveSymbolFromStatementList/after/src/a.py

@@ -1,6 +1,7 @@
 if True:
     pass
 
+
 while True:
     for _ in range(10):
         # comment