add support for remote firefox and webkit

[Ehsan-U]

#277

[elacuesta]

Thanks for the contribution. Unfortunately, I don't think it's a good idea to reuse the PLAYWRIGHT_CDP_URL setting for a non-CDP connection.

[Ehsan-U]

Thanks for feedback!

Another option would be to add a separate setting for Firefox and WebKit using the PLAYWRIGHT_RDP_URL

RDP is Remote Debugging Protocol. While I'm not certain if Playwright uses this protocol to connect to Firefox and WebKit, I can't think of another way it might be done.

[elacuesta]

Indeed, see #283.