fixes https://github.com/TryGhost/Team/issues/2432
Adds outbound_link_tagging setting (enabled by default and behind
feature flag). If the feature flag is enabled, and the setting is
disabled, we won't add ?ref to links in emails.
This includes new E2E tests for email click tracking, which were also
extended to check outbound link tagging (for both MEGA and the new email
stability flow).
Also fixes a test fixture for the comments_enabled setting.
refs https://github.com/TryGhost/Toolbox/issues/479
- this includes a handful of improvements to get Playwright working on a
local environment including:
- adding `testing-browser` environment so we don't nuke `development`
environments, and makes all the necessary changes to get Ghost to
behave when this is running
- stopped running one global instance of Ghost as this doesn't provide
a clean environment
- copies a few default fixtures that are needed for the new
environment