Migration Flow Improvements: Feature the 14-day refund window and rework the headline and subcopy

[merkushin]

Details

In the Upgrade plan screen (client/blocks/importer/wordpress/upgrade-plan):

• Feature the 14-day refund window more prominently.
• Rework the headline and subcopy to not hide the fact that the user requires a Creator plan to access migrations. Confirm copy with @JanaMW27

Design:

[Imran92]

Rework the headline and subcopy to not hide the fact that the user requires a Creator plan to access migrations

@merkushin Looks like the existing sub-copy doesn't hide the requirement for the creator plan as it explicitly mentions it. Do we still need to change it?