Test: Terminal DOM renderer

[Tyriar]

#46954

Complexity: 3

• macOS @isidorn (or Linux)
• Windows @sbatten

The terminal now has a DOM renderer which can be turned on via a notification that presents itself when the average time it takes to render is above 50ms/frame. The condition would be a little hard to verify unless you have a machine that has issues but you can turn it on manually using "terminal.integrated.rendererType": "dom".

Please test what you normally do in your terminal. Note that the DOM renderer is intentionally not as featureful or perfomant as the standard one, if you find anything that you think should be supported or is particularly slow please file an issue.