Implement update mode for integration tests

[AlexanderSavelyev]

Background
It is hard to update tests references for python tests

Solution

• Create new mode "-u" for api/tests/integration/test.py
  • This mode will update the tests in "ref" folder for the executed tests
  • If ref/$folder/$platform/$test exists, then update the test
• Create new function compare_diff (filename, data, stdout=True, diff_fn=find_diff): str where
  • filename - full file name
  • data - text to read (update) from
  • stdout - boolean to print into stdout (filename + ':SUCCEED' if no diff else filename + ":FAILED", then diff )
  • diff_fn - lambda to compare two strings (find_diff(ref_txt, txt) by default)
  • function should return None if no diff, or the diff string
  • New function compare_diff should also use "-u"
  • Find all places where "find_diff" is used and replace by compare_diff
• Move moleculeLayoutDiff and reactionLayoutDiff to util.py and use the -u parameter