Set Email to receive notifications

**User Story:**
As a funder
I want to set a specific email for where i receive notificaitons
So that i can ensure that it is an actively monitored email and can take action when needed

**Acceptance Criteria**
**Form Initation**
GIVEN I am creating a bounty
WHEN I navigate to the additional information step of the new wizard
THEN I should see an input field for me to enter the email where i want to receive email notifications
AND that email entered should not be shown anywhere on the bounty details page

**Product & Design Links:**
https://www.figma.com/file/8AFLrc4dx9xnMXUkWOAaAR/Existing-Bounties-Updates?node-id=33%3A1854

Start with the additional information step of the new bounty wizard and the bounty details page, using the linked Figma design for the intended placement and visibility. Trace how the form data is handled for creating a bounty and how notification email recipients are stored or used. Done means the email can be entered for notifications and does not appear on the public bounty details page.

Written by the indexing model from the issue text.