Investigate usage of playwright-driver functionality rather than having a custom driver

[teodesian]

Apparently it has a stdin/stdout communication mechanism which would result in possibly less code for me to maintain.

Primary risks:

1. may result in specification handling code having to move into perl
2. browser initialization code may become more complicated
3. dealing with promises may become a bit strange; the existence of both a sync and async python client may imply this?

Anyways, it's not documented, but the python module apparently uses it and I can likely crib extensively. Would result in a good writeup at the least for driver authors coming after me.