Support for parsing Onion Service circuit IDs

Tasks

• Add support for parsing Onion Service circuit IDs (tpo/onion-services/eotk-log-parser!1).
• Add sample logs (examples here).
• Aggregate page hits by site and circuit ID.
• Optionally decode the circuit identifier to the actual circuit number (check tor(1) manpage for details). Not needed right now (as this tools is not intended to close circuits).
• Release version 1.0.0 (major number bumped due to breaking changes).

Time estimation

• Complexity: very small (0.5 day)
• Uncertainty: low (x1.1)
• Reference (adapted)