fix: ignore empty source filters in badge count

[adriangmweb]

Summary

• count only source filters with meaningful values in the rule badge
• keep page URL excluded from the advanced filter badge count
• require request payload filters to include both key and value before counting
• add regression coverage for empty/default filters, empty array entries, request payload edge cases, and legacy object-shaped filters

Context

This ports the fix from requestly/requestly#4723 after the HTTP Interceptor code moved to this repository. It addresses the original bounty issue requestly/requestly#3826.

Verification

• npm test -- RequestSourceRow/utils.test.js --run (could not run locally: fresh checkout has no node_modules, vitest command not found)
• standalone Node validation of the filter-counting cases passed