Report cosmetic rules to apps via program events

[ameshkov]

Issue Details

This is a continuation of #180, but on a different level.

In order to show cosmetic rules in the programs' filtering log we need to be able to report cosmetic rules programmatically and not just write them to the browser console.

Proposed solution

1. Provide an API that allows reporting cosmetic rules from the content script.
2. This API must only be available when the content script operates in the "debug" mode, i.e. when the filtering log is open in the program.

Alternative solution

No response