Convert hand raise lead to use eventHub for opening modal

What does this MR do and why?

Convert hand raise lead to use eventHub for opening modal

• this is an incremental step in being able to separate button from the modal in the dom. Eventually we want to try and only ever load the modal into the DOM once. This change will help use be able to get there.
• see plan in #443674 (closed)
• All instances of the hand raise modal/button were verified to be fully covered by browser tests in Add full test coverage for hand raise lead subm... (!150146 - merged)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

no change

Screen_Recording_2024-04-12_at_3.32.59_PM

How to set up and validate locally

note covered in this spec

1. Setup to simulate SaaS and restart GDK
2. Allow local network connections
   • Make sure Admin > Settings > Network > Outbound requests is set like the below This can be skipped if not desiring to see modal submission work.
3. Setup CustomersDot locally. This can be skipped if not desiring to see modal submission work.
4. Navigate to any group you are owner of and go to Settings -> Billings
5. Click on 'Talk to an expert'.
6. Fill out the form and submit.

Related to #460508 (closed)