Selectively hide public email on profile page

What does this MR do and why?

This MR will hide the display of a user's public email if the feature flag hide_public_email_on_profile has been set to true for the group actor equal to the value of the user's provisioned_by_group.

This is a short term work around.

Screenshots or screen recordings

Feature flag disabled	Feature flag enabled for provisioned_by_group

How to set up and validate locally

1. In rails console

   group = FactoryBot.create(:group)
   scim_identity = FactoryBot.create(:scim_identity, group: group)
   user = FactoryBot.create(:user, :public_email, provisioned_by_group_id: scim_identity.group.id)
   Feature.disable(:hide_public_email_on_profile)

2. Visit profile page for user E.g. http://localhost:3000/test-user
3. Observe user email is displayed.
4. In rails console

   Feature.enable(:hide_public_email_on_profile, group)

5. Observe user email is not displayed.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/351723