Send registration confirmation email with verification link, remove u…

[ydahal1]

…nverified accounts that are older than 12 hrs

ISSUE - #56

1. Weather or not to verify user email, can be configured during the time of adding application
2. If email settings are not added to back end envs, users won't have this option
3. HPCC applications are set not to verify email
4. Every 1 hr, a job runs and removes unverified users that are 12 hours or older
5. Once user verifies the account, the confirmation code will be removed from users table and will be added to registration confirmation codes table
6. If the user tries to verify account with link that is older than 12 hrs - they will get in-valid verification link message
7. If user tries to verify already verified account, they get email already verified response
8. Auth service default user have account verified flag true by default
9. If a user uses roles are added for new application, no verification link will be sent
10. Users can request to for new verification email

[konstagap]

Looks good!