Allow users to extend SaaS trial in-app

Summary

Users take out SaaS trials and frequently do not get a chance to complete their evaluation prior to the 30-day trial ending. This generates requests of the sales and support teams to extend the trial. The average support ticket costs the team ~5 minutes per request, and they are averaging ~60 requests/month.

Proposal

Create a mechanism in the GitLab.com Billing page which allows users a one-time extension of an existing trial.

Success Criteria

1. The Trial extension should be available to any users with access to the GitLab.com Billing page
2. The Trial extension should be available one time per namespace
3. The Trial extension should be available when the trial is active or expired
4. The updated trial end date should be sent to the appropriate SFDC record