@tapjs/stack needs to be able to produce "conventional" js stacks

[isaacs]

The node --test reporter is doing some fancy parsing stuff with error stacks, but the way that tap pares them down doesn't get the full treatment, even though it's quite a bit nicer on its own, it still looks like dog's dinner when it's util.inspect()ed all on one line.

Need to produce a stack string with the at, single full absolute filename, etc.

Should be an option to CallSiteLike.toString() to produce a line like this, the logic shouldn't have to change too much otherwise.