Migrate to node-w3capi instead of sending request to API port directly.

[jennyliang220]

https://github.com/w3c/node-w3capi

[jennyliang220]

And use feature w3c/node-w3capi#89.

E.g. in lib/validator.js

before:

let groupsCharters = [];
deliverers.forEach(deliverer => {
    // Skip finding charter for the TAG which doesn't have any charter
    if (deliverer === TagID || deliverer === AbID) return;

    delivererPromises.push(
        new Promise(resolve => {
            w3cApi
                .group(deliverer)
                .charters()
                .fetch({ embed: true }, (err, charters) => {
                    resolve(charters);
                });
        })
    );
});
groupsCharters = await Promise.all(delivererPromises);

after:

const  groupCharters = [];
deliverers.forEach(deliverer => {
    // Skip finding charter for the TAG which doesn't have any charter
    if (deliverer === TagID || deliverer === AbID) return;

    groupCharters.push(await w3cApi.group(deliverer).charters().fetch({ embed: true }))
});

[jennyliang220]

w3c.group({type: "wg", shortname: "xxx"}).fetch