DHT Info hash indexing support

What's Changed

• Refactored the Piece- & File pool to a merged data pool by @yoep in #10
• Update reqwest requirement from 0.12 to 0.13 by @dependabot[bot] in #12
• #6: Implemented DHT info hash indexing by @yoep in #11

Full Changelog: v0.1.0...v0.2.0