e2e: Setup service to mock and test emails

[ericpgreen2]

Two goals:

1. We shouldn't have SendGrid send actual emails to [email protected] (it's a waste of resources)
2. In our Playwright tests, we should be able to programmatically fetch email contents and simulate link clicks (e.g. an "Open dashboard" link)

A couple ideas:

1. Extend the mockSender service (in email_test.go) to expose emails over an API that the Playwright tests can call
2. Use a service like Mailpit to capture & expose emails

[begelundmuller]

@ericpgreen2 We currently have a console sender that logs sent emails to the STDOUT. Would you be able to capture and check them from there?

[ericpgreen2]

(Discussed in Slack that we'll go with the Mailpit approach)