Check EOF for all file types

[sarjona]

Currently, we are only checking EOF for PHP files (as described in MDLSITE-6397). However, as @scara raised in MDL-77396, it would be great to also add it to CiBoT for other file types (like CSS).
@stronk7 mentioned (in case it helps to implement it): "We don't look for other files within moodle-cs. Surely we need to add a global whitespace checker to CiBoT (pretty much like the post-checks do, but in CiBoT, allowing zero cases).". 

[stronk7]

For the records, I've been looking to the current Illegal whitespace script that we already have (and use in the post-commit checks), but I'm not sure if it's going to be suitable to be used by CiBoT (pre-commit checks), because it's missing support for some utilities like knowing about the affected files in the patch to examine and other details.

In any case... I'll give to that a try... maybe we can reuse it with some hackery... let's see.

Ciao :-)

[stronk7]

Today, when looking to other stuff (some tests in local_ci), I've seen that, with this simple test, we can know when any file has an EOL @ EOF:

[[ $(tail -c1 path/to/file) && -f path/to/file ]]

And it shouldn't be very hard to add it as a main check to be reported in the new "overview" section of CiBoT (see #297). Maybe the only problematic point is to be able to exclude any binary files (images, mainly, ...) that are not subject to the rule.

I'll try to give to this a try...