[AmazonPriceTrackerBridge] Improve Amazon scraper logic (#761)
[AmazonPriceTrackerBridge] Improve Amazon scraper logic (#761)

- Now works on all websites, and even with products
  with multiple prices
- Closes #750
RSS-Bridge/rss-bridge,sebsauvage/rss-bridge,Frenzie/rss-bridge,RSS-Bridge/rss-bridge,simonbru/rss-bridge,ORelio/rss-bridge,teromene/rss-bridge,simonbru/rss-bridge,Riduidel/rss-bridge,kranack/rss-bridge,kranack/rss-bridge,Riduidel/rss-bridge,RSS-Bridge/rss-bridge,ORelio/rss-bridge,Frenzie/rss-bridge,ORelio/rss-bridge,kranack/rss-bridge,teromene/rss-bridge,kranack/rss-bridge,Riduidel/rss-bridge