Enable clients to set up a contact email address as support channel for their form (in Settings)

## Update to settings page to add contact email (support flows)

### User stories

> **As an end user filling out a form**
> I want a way to get in touch with the program/service/form owner
> So that I can get help and/or indicate that I've encountered an issue

> **As a client administering a form**
> I want my end users to have a good experience and feel supported
> So that they can complete the form, reach their goals, obtain benefits, etc.

> **As the GC Forms team**
> I want a way to get in touch with the form / service
> So that our support team doesn't get inundated and receive tickets from the public

### Questions/considerations:

- Where is this data stored?
- What is its data classification?
- How is it being used, displayed, and/or shared?

### Key elements:
- New sections under Settings/ Forms management
- "Support channels" h2
- Input field, styled similarly to the repeating sets custom button input fields (option for scaling the channels in the future)
- "Save changes" secondary button

### [Figma designs](https://www.figma.com/design/YoCpkitdwq2DGnp3lh0M4i/Pause-and-resume?node-id=5345-12229&t=7R6K3JsB1QQen14q-4)

### Future:
- Reorganize the settings page given the new options in the Pause + Resume flows
- Adding rich text field to add description or more channels in a contact card (?), whichever works best
- Consider a future onboarding experience to set this up from the get-go