2623 20 add new sync provider change to modal

[LukeFinch]

Why does this PR exist?

Closes #2623

Sync providers list was getting too long in a dropdown menu, time to move it into a modal.

What does this pull request do?

• Moved 'add new sync provider' next to the heading – (Happy to move this back, but it feels better there for me with a long list of sync providers)
• Moved options into a modal
• Providers can have a description
• Added a 'Beta' value - shows a beta badge (reused from SecondScreen) - for some visual consistency

Testing this change

Additional Notes (if any)

[changeset-bot[bot]]

⚠️ No Changeset found

Latest commit: ffe9b1ab37cc577366eb84b3a479cd55a586d8d7

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR