Adds 2 new config variables HACKGT7_SPONSOR_EMAILS and HACKGT7_SPONSOR_DOMAINS (can be secrets) to control sponsor acceptance
Applications to the sponsor branch are accepted/rejected immediately based on whether the user's email (which has to be verified first in Ground Truth before a user can access Registration) matches the domain or email whitelist
HACKGT7_SPONSOR_EMAILS
andHACKGT7_SPONSOR_DOMAINS
(can be secrets) to control sponsor acceptance