Add “Context” Information to Filtering Log (Request Frame/Document Context)

### Issue Details

While AdGuard's Filtering Log includes the source domain of a request (which aligns with what uBO calls "Root Context"), it currently lacks the context indicating the specific document or frame where the request or element actually appears — information that is visible in uBlock Origin's logger under "Context".

See:

| AdGuard | uBO |
| ------------- | ------------- |
|  |  |

This data is extremely useful for:

- Debugging rules applied to embedded content (e.g., iframes or third-party domains),

- Understanding cross-domain behavior of rules,

- Identifying which part of the page structure is triggering a rule.

Related issues:

- https://github.com/AdguardTeam/AdguardFilters/issues/201401
- https://github.com/AdguardTeam/AdguardFilters/issues/203513#issuecomment-2828252102

### Proposed solution

Please consider adding a new field to the Filtering Log — something like "Context", "Document Context", or "Request Frame" — that displays the specific document or subframe where the request is executed. This would improve transparency and debugging capacity for advanced users and filter list maintainers.

### Alternative solution

_No response_