handle registered user with promo

[MashB]

DevBoard Task

https://dev.azure.com/TDEI-UW/TDEI/_workitems/edit/2389

Changes Introduced

• Handled use case where registered user trying to scan same promo code again and registers , in this case user will not be thrown error instead will be responded with user profile details with token for deeplink navigation.
• Handled use case where registered user trying to scan different promo code and registers, in this case user will be associated with new promo code project group and will be responded with user profile details with token for deeplink navigation.
• Refactoring changes
• Added unit test case

Impacted Areas for Testing

• Test Registered user with same promo code
• Test Registered user with new promo code