Deduplicate rapidly repeating blocked requests in Analytics

### Issue Details

Currently, the figures shown in AdGuard's Analytics (Blocked Requests, Trackers Blocked, and Saved Data) are heavily inflated. When AdGuard blocks a connection, many apps or tracking scripts enter an aggressive retry loop, attempting to reconnect hundreds or thousands of times within a very short period.
AdGuard counts every single one of these automated retries as an individual "block". Consequently, the "Saved Data" estimation also skyrockets unnaturally. These inflated numbers do not reflect the actual amount of unnecessary data or normal requests that AdGuard saved during regular browsing, making the analytics unreliable as a practical reference.

### Proposed solution

Implement a "Unique Block Count" or deduplication logic for the analytics.
If identical requests (e.g., to the same domain from the same app) are made repeatedly within a short timeframe (e.g., 1 minute), they should be grouped and counted as "1" unique block. This would display a realistic estimate of AdGuard's true contribution to network efficiency.

### Alternative solution

Since processing and deduplicating these logs might require additional system resources, it would be completely acceptable to implement this advanced, highly accurate analytics view exclusively as a "Pro (Premium) version" feature.