Parity: Add support for `example.org/path` cosmetic rules

[ameshkov]

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Issue Details

uBO added support for specifying path in cosmetic rules: https://github.com/gorhill/uBlock/commit/8b696a691a

In order to maintain parity we need to support this in CoreLibs as well.

Proposed solution

• We can internally convert it to $path modifier.
• We will need to update the documentation in the knowledge base

• Linked tsurlfilter issue: https://github.com/AdguardTeam/tsurlfilter/issues/169
• Linked CoreLibs issue: https://github.com/AdguardTeam/CoreLibs/issues/2012