Jetpack Search: add WP.com Search purchase Thank you note

[AnnaMag]

Changes proposed in this Pull Request

• Adding Search specific Thank you message and redirect the Customizer to setup/try the product
• Add tracking to match the Jetpack purchase, extending the latter with the site info.

Testing instructions

• Purchase Jetpack Search for a WP.com at http://calypso.localhost:3000/checkout/:wpcomsite/jetpack_search_monthly
• verify that the Thank you note is displayed with a relevant text
• verify the redirect to the Customizer

Fixes #42285

[matticbot]

Test live: https://calypso.live/?branch=add/wp-thank-you

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~341 bytes added 📈 [gzipped])

name      parsed_size           gzip_size
checkout      +1032 B  (+0.1%)     +337 B  (+0.1%)
plans           +15 B  (+0.0%)       +4 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[gibrown]

Works great and code lgtm