Add assert NoConsoleErrors method?

[ebebbington]

Really all this feature should be is: The user should be able to assert there are no errors in the console (and also be able to check and exclude?), so some examples could be

function assertNoErrors(exclusions: string[] = []) {
  // get err console messages
  // check non exist or exlucde the exclusions then check
}

const browser = await buildFor(...)
await browser.goTo(...)
await browser.assertNoErrors(['favicon.ico'])

Requirements:

• Should be able to assert console has no errors (this aids in things like browser testing, all integration tests could pass, but webpack could silently fail, vue errors in the console and nothing is rendered)
• Should be able to exclude errors when asserting (eg favicon.ico 404, if a user knows this will be an error, asserting shouldnt fail as this doesnt matter