My Jetpack: add connection animation

[IanRamosC]

Proposed changes:

• This PR adds a new animation to the connection step on My Jetpack. This animation is intended to lessen user's confusion while Jetpack is connecting.

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

pbNhbs-bJV-p2

Does this pull request change what data or activity we track or use?

Testing instructions:

• Spin up a JN site with Jetpack Beta pointing to this feature branch
• Go to My Jetpack
• Click to active your site with one click
• Confirm that the animation looks like the video above and there's no weird behavior

[github-actions]

Are you an Automattician? The PR will need to be tested on WordPress.com. This comment will be updated with testing instructions as soon the build is complete.

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

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