New verbose logger to debug output

[holgerd77]

The current debug output triggered with e.g.

DEBUG=devp2p:* node -r ts-node/register ./examples/peer-communication.ts

is very hard follow and use for debugging since it is extremely verbose, in the case of ETH debugging output printing out dozens to hundreds of lines with the full message payloads to the CL.

This PR adds a new verbose logger for the debug output which can be used like this:

DEBUG=devp2p:*,verbose node -r ts-node/register ./examples/peer-communication.ts

This preserves the currently implemented behavior. Logging defaults now to a non-verbose output - shortening long peer IDs, block hashes and - most important - message payloads, which should be a lot friendlier for the everyday debug situation.

Exemplary verbose output:

Exemplary non-verbose output, similar situation:

[coveralls]

Coverage increased (+0.1%) to 87.5% when pulling 04e6537 on add-verbose-logger into 7cf880f on master.

[evertonfraga]

Right, the benefit is pretty obvious here :)

Before:

After:

[holgerd77]

@evertonfraga Your example is even more convincing, thanks! 😋