Is your feature request related to a problem? Please describe.
Selenium 4.0 (now in Beta) supports proxying CDP Requests across Grid.

It would be nice if we could use the WebdriverIO Devtools Service to run those commands against a Selenium 4.0 Grid.

Describe the solution you'd like
When providing a remote machine in the config, such as:

    runner: 'local',
    hostname: 'my.grid.ip',
    port: 4444,

And providing the devtools service

services: ['devtools'],

I should be able to call commands in my test like:

browser.cdp('Browser', 'getVersion')

Describe alternatives you've considered
n/a

Additional context
I'm happy to take a shot at this PR if you'd accept it. I believe the change will occur in here:

         this.puppeteer = await puppeteer.connect({
-            browserURL: `http://${chromiumOptions.debuggerAddress}`,
+            browserWSEndpoint: `ws://${this.config.hostname}:${this.config.port}/session/${this.sessionId}/se/cdp`,
         })

Of course with some conditionals added depending on if

1. User provided a custom debuggerAddress
2. Whether a local run or a remote host/port is being used
3. If it's Remote, check if it's a Selenium 4.0 Grid that accepts those commands (can probably look at returned capabilities, which exposes this endpoint)