fix/feat: JSONP comma-prefix, trending_analysis_merged() (v0.2.10)

Fix: _handle_network_response was not stripping ')]}',\n' prefix (with
comma) before JSON parsing, causing relatedsearches responses to silently
fail. Added comma variants (6-byte and 5-byte) to prefix removal logic
in both sync and async handlers — fixes related_topics/queries in browser
mode when API returns comma-prefixed format.

Feat: trending_analysis_merged() — returns both topics and queries from
a single browser navigation. Both sync (TrendReq) and async (AsyncTrendReq).

Also: extra 5s wait in _capture_analysis_responses when responses missing.