Move invocations of Onboarding::ProgressService to ee part 1

What does this MR do and why?

Move invocations of Onboarding::ProgressService to ee part 1

• Onboarding is only an EE concept for SaaS. Therefore, we should move the invocations out of CE and follow ce/ee separation concepts in https://docs.gitlab.com/ee/development/ee_features.html
• Remove async functionality from the Onboarding::ProgressService as it isn't used.
• This MR is part 1 and will not get all of the cases.
• see #472657 (closed)

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Related to #472657 (closed)