New Feature: allow to override debugerror

[lamuertepeluda]

Use Case

I need to intercept the logs from both errors and standard debug log messages, e.g. for sending them to a backend.

Logging standard messages is easy by overriding the debug.log function, e.g. as shown here: https://groups.google.com/g/jssip/c/5LWejj-N_sU, i.e.

JsSIP.debug.log = (...args) => {
    const logString = args[0].replace(/%c/g, '');  // Remove coloring syntax used by debug tool.
    logger(logString);
};

Logging debugerror is however impossible, since it's internally defined and bound to console.warn() in an isolated scope.
E.g. like in this commit, or here in the sources

var debugerror = require('debug')('JsSIP:ERROR:Socket');
debugerror.log = console.warn.bind(console);

Because of this implementation, exposing the debug module as it's done here is not enough.

Proposal

Have an option for overriding the default logger(s), with default to the current behaviour.

I can try a PR if you like this idea.