Add a new HTTP tracker client binary

[josecelano]

For testing purposes, it would be very helpful to have a command like this:

cargo run --bin http_tracker_client https://tracker.torrust-demo.com 9c38422213e30bff212b30c360d26f9a02136422

The UDP client code has already been moved from the testing code to the production code. We can also move the HTTP tracker client used in tests to production code.

This script can be used to manually test the HTTP tracker but also for E2E tests in the future.