feat(modules/file/check_hash): command line friendliness

Named parameters on the command line are given on the form "key=val".
This makes things awkward when Salt command line needs to be written on
the form:

    salt file.check_hash /etc/myfile hash=md5=abcabcabc

I'd much prefer

    salt file.check_hash /etc/myfile md5:absabcabc

Note that this change is not backward compatible.
feat(modules/file/check_hash): make backward compatible
fix(modules/file): formatting
Merge pull request #11034 from JensRantil/less-awkward-check_hash

Less awkward file.check_hash(...)