SPIKE: Move all purchasing flows to GitLab.com

Summary

This is a research issue to break down the work to move SaaS purchase flows to GitLab.com. The expected output includes creating applicable BE and FE issues and providing an estimated weight where possible.

Please see epic: gitlab-org/growth&36 (closed)

Options Comparison

Option	Pros	Cons	Notes	Supporters
Move components to GitLab	We have full control over how components behave inside GitLab	Duplicated code between 2 projects Harder to maintain 2 copies of the same component
Move components to shared package then use in GitLab	Easier to reuse components between 2 projects Reduce the components code used in each project by extracting it to external one	One extra project to maintain
Compose new components for GitLab	Easy to adopt new UX/UI design More control over SaaS specific purchase flows	New components to maintain Not reusing existing components We need to rewrite all JS tests to accommodate new components		@esybrant, @rhardarson, @vitallium, @aalakkad
Serve pages through an iframe from CustomersDot	No need to create another project or to duplicate components Faster MVP	Ambiguity on how to implement Uncertainty on how to handle user sessions and data passed from HTML to Vue	invalidated by @vitallium

Action points

• ask UX if they expect any change in the components when we move flows to GitLab or it will stay the same