feat(crawler): add Display trait

formatted printout with compressed info so it doesn't clutter the output with many newlines
removed (super) from pub(super) because the crawl mod will be taken out and used by other tests from this binary (source code tree)

example of the printout:

 server: build_version: 1.9.4, server_state: connected, server_uptime: 36
 peerlist:
[00034]: 100.24.12.73:51235                     AyT/MLgoFGxwXrV8t0WVxZFQw8LgV4ypYXn8rp5ewGzd
[out]:                          version: rippled-1.9.4                  shards: None ledgers: Some("77995485-78015485")

[00034]: 13.48.204.149:51235                    ArO1nS71bRFvZPx3qWtev20+k3D5B4Aji9k68Wgprjyu
[out]:                          version: rippled-1.9.4                  shards: None ledgers: Some("77995485-78015485")

[00034]: 13.49.231.59:51235                     AmRS+0qkiLq9fwm7y127MsHOWjMriljE3bdhFyMHxpIN
[out]:                          version: rippled-1.9.4                  shards: None ledgers: Some("77995485-78015485")

[00034]: 18.232.83.47:51235                     A7t8t5IDUoV8r5jFNZ/u+ym9nWx+5mSMnRiYuxTBkV9f
[out]:                          version: rippled-1.9.4                  shards: None ledgers: Some("77995485-78015485")

[00034]: 3.122.10.154:51235                     A/7PxSIKPdsfBuoI4u87SRup4yCK+Ric+ijvhyPmq8x7
[out]:                          version: rippled-1.9.4                  shards: None ledgers: Some("77995485-78015485")

[00034]: 34.230.16.97:51235                     AmMC5HVYfRTFKKO+O+enrnm70GE0SknM8pXrcYnV2sKa
[out]:                          version: rippled-1.9.4                  shards: None ledgers: Some("77995485-78015485")

runziggurat / xrpl

feat(crawler): add Display trait #129