Display Cloud banner by default on self-host + revamp copy

[gmourier]

Expected behavior

• The Cloud banner is displayed by default when running a self-hosted instance (see attached screen)
  • It should not be displayed if the mini-dashboard is opened for a cloud instance; a query parameter exists for that cloud_banner=false
• The banner can be closed and not displayed again
• Banner's copy changes
  • Banner title: "Scale up with Meilisearch Cloud 🚀"
  • Banner text: "Faster, smarter search—no maintenance needed. [Start free] with no commitment." (use current link)

Current behavior

• The banner does not show up by default when opening the mini-dashboard on a self-hosted instance

Screenshots

[mayasssh]

Slightly updated the copy (punctuation!)