New rule: suggest setting LC_ALL when calling sort

[raphael-proust]

For bugs

• Rule Id (if any, e.g. SC1000): None (yet?)
• My shellcheck version (shellcheck --version or 'online'): online
• I tried on shellcheck.net and verified that this is still a problem on the latest commit
• It's not reproducible on shellcheck.net, but I think that's because it's an OS, configuration or encoding issue

For new checks and feature suggestions

• shellcheck.net (i.e. the latest commit) currently gives no useful warnings about this
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

#!/bin/sh
cat /tmp/some_file | sort

Here's what shellcheck currently says:

No issues detected!

Here's what I wanted or expected to see:

It should suggest to set LC_ALL=C locally in the script:

Did you mean
cat /tmp/some_file | LC_ALL=C sort

Setting LC_ALL ensures it's all sorted the same on all machines.