Add support for "trusted" scriptlets

[ameshkov]

Trusted scriptlet are the ones that are only allowed in filter lists marked as "trusted":
AdguardTeam/Scriptlets#106

The difference is that their name is strarted with a trusted- prefix.

For instance:

example.org#%#scriptlet('trusted-click-element', '#banner #close');

[ameshkov]

Currently, we allow all scriptlets in trusted lists only. As a part of this task consider allowing scriptlets (but not trusted ones) in all lists.