Feat: saas starter version

What does this MR do and why?

Issue: https://jihulab.com/gitlab-cn/gitlab/-/issues/4244

• Making plan component to show a yearly price instead of monthly and yearly which will cause confusion.
• Introducing Starter version for both purchased and non-purchased customers.

Feat: saas starter version

• Add feature flag for saas starter feature.
• Add JH plan component for starter version.

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