Address the issue "file.managed is TOO secure"

As mention here [file.managed is TOO secure](https://github.com/saltstack/salt/issues/9272) *file.managed* is too aggressive in enforcing a standard file format for secure hash checksums.

This patch use regular expressions, line by line, on any text file format, attempting to discover at least one SHA* or MD5 candidate.

Only two files are altered:
 1. states/file.py
 1. modules/file.py

The former has alterations only in documentation.  The latter replaces a few lines out of *file.managed()* with a call to a new function called *extract_hash()*

This is my first pull request to a multi-branch project.  Please let me know if I should have done it differently.

(You will no doubt see that I overdosed on logging.  Hopefully that will facilitate reviewing prior to approval.)