Help Center: send missing url

[heavyweight]

Fixes https://github.com/Automattic/dotcom-forge/issues/9774

Proposed Changes

• We weren't sending the customer site in the user fields before creating a conversation.

Why are these changes being made?

• The site url should be passed when submitting the user fields

Testing Instructions

• Build this PR
• Use the help-center-experience feature flag
• Create a new conversation
• Ensure that the url is passed when submitting the user fields

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-afc3dadd8750fcbe133e46d99f66cbcfa300f814

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-afc3dadd8750fcbe133e46d99f66cbcfa300f814&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-afc3dadd8750fcbe133e46d99f66cbcfa300f814&env=a8c-for-agencies

[matticbot]

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

Async-loaded Components (~32 bytes added 📈 [gzipped])

name                               parsed_size           gzip_size
async-load-automattic-help-center        +99 B  (+0.0%)      +32 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.

[arcangelini]

LGTM

[agrullon95]

LGTM. I verified my site url is sent in the messaging_url parameter.