Hosting onboarding: preserve hosting flow even for already existing users

[zaguiini]

Related to pet6gk-tn-p2#comment-464

Proposed Changes

We should show the empty sites dashboard CTAs when the user comes from /start/hosting, even if they already have sites. Not doing so breaks continuity.

Testing Instructions

On your existing WPCOM account with sites, browse /start/hosting and continue.

You should be redirected to /sites and see the centralized CTAs asking whether you'd like to create or import a site (instead of the sites list):

"Migrate a site" should point to /setup/import-hosted-site?source=sites-dashboard&hosting-flow=true.

Also verify that ref=calypso-nosites is NOT added as a query parameter if your account already has a site.

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-185e8518d7434d6c5b7c68bb12de9fd0f4684e5e

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-185e8518d7434d6c5b7c68bb12de9fd0f4684e5e&env=jetpack

[matticbot]

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

Sections (~23 bytes added 📈 [gzipped])

name             parsed_size           gzip_size
sites-dashboard       +123 B  (+0.0%)      +23 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.

[a8ci18n]

This Pull Request is now available for translation here: https://translate.wordpress.com/deliverables/8072700

Thank you @zaguiini for including a screenshot in the description! This is really helpful for our translators.

[a8ci18n]

Translation for this Pull Request has now been finished.