Add support for redisClient.v4 commands

[bizob2828]

Is your feature request related to a problem? Please describe.

A customer reported upgraded from v3 to v4 and was using the legacy mode and it didn't capture spans.

Feature Description

const express = require("express");
const app = express();
const port = 3000;
const redis = require("redis");
const redisClient = redis.createClient({
  url: "redis://127.0.0.1:6379",
  legacyMode: true,
});

app.get("/redis-v4", (req, res) => {
  debugger
  redisClient.v4
    .set("baz", "qux")
    .then(() => redisClient.v4.get("baz"))
    .then((x) => {
      res.send(`baz is: ${x}`);
    });
});

redisClient.connect().then(() => {
  app.listen(port, () => {
    console.log(`Example app listening on port ${port}`);
  });
});

Additional context

This appears to be as simple as wrapping client.v4 with the same stuff as client.

[workato-integration]

https://new-relic.atlassian.net/browse/NR-271194