Add an optional parameter to JetpackConnectHelpButton to link to a different URL

[DanReyLop]

Changes proposed in this Pull Request

When HappyChat is not available, the JetpackConnectHelpButton becomes a simple link that sends the user to 'https://jetpack.com/contact-support'. This PR makes that URL customizable.

How to test

There's no code that calls JetpackConnectHelpButton with a url prop, so there's no way to test this. You can test there has been no regression by starting the Jetpack connection flow and clicking on the "(?) Get help setting up Jetpack" link.

Note: This is a required refactor for the new "Woo DNA" flow, implemented in #41798

[matticbot]

Test live: https://calypso.live/?branch=woodna/override-jetpack-help-url

[matticbot]

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

App Entrypoints (~6 bytes added 📈 [gzipped])

name         parsed_size           gzip_size
entry-login        +58 B  (+0.0%)      +10 B  (+0.0%)
entry-main         +17 B  (+0.0%)       -4 B  (-0.0%)

Common code that is always downloaded and parsed every time the app is loaded, no matter which route is used.

Sections (~167 bytes added 📈 [gzipped])

name             parsed_size           gzip_size
jetpack-connect       +295 B  (+0.1%)     +121 B  (+0.1%)
accept-invite         +166 B  (+0.1%)      +46 B  (+0.1%)

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

Async-loaded Components (~49 bytes added 📈 [gzipped])

name                          parsed_size           gzip_size
async-load-signup-steps-user       +166 B  (+0.1%)      +46 B  (+0.1%)
async-load-design-blocks            +41 B  (+0.0%)       +3 B  (+0.0%)

React components that are loaded lazily, when a certain part of UI is displayed for the first time.

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.

[vbelolapotkov]

LGTM! 👍