Added a Screenshot only option to playwright tests

[infinitejest69]

This is just a proposed approach to use visual screenshots only, this is my first actual contribution to an open-source project so happy to correct any process i did no follow like formatting etc. i didn't see a contributions readme so might have missed obvious stuff

[infinitejest69]

@dotnet-policy-service agree

[infinitejest69]

From discussion #655

[SimonCropp]

can you add some documentation for this feature

[infinitejest69]

Pushed changes hopefully they are in the right direction

[SimonCropp]

LGTM

[SimonCropp]

this is now deployed