refactor: split checks into individual rules

[fzipi]

what

• create a common core to easily add and test new checks
• split checks from the main cli to individual files with common parameters
• create helper classes to make things more pythonic
• add documentation on how to add additional tests

why

• create a standard format to make easier to add more checks
• improve testability

[fzipi]

Finally got the time (and will) to finish this refactor.

[airween]

After my first review I have some comments.

[airween]

chained is not used here. In the current code it used to get the rule ID, but you don't use that (eg. in message), so you should remove this, or use the rule ID in message, for eg.

[airween]

In the meantime, an addition was made to the original code: we have added a new function to check whether the rule has a tag for its filename. I think we need this here too. For details please check #27

[airween]

Here you don't use the rule ID either so you should remove this line and below the block (or add rule ID to the message, for eg.).

[airween]

Does this class have the same functionality like ctl_audit_log above? Why are both necessary?

[airween]

Here you don't use variable current_rule_id, you should remove it or add it to message.

[airween]

In current (old) implementation I explained here why is this hack needs. I think that would be useful here too. (This is the parser's deficiency.)

[airween]

Here you don't need to iterate through all actions, just use your implemented get_id(). I think that would make the code a bit more clear. (But you will need the id in two formats: int and string)

[airween]

I think the explanation from current code would be useful here.

[airween]

And here too from here.