Issue Summary

New Portal-only customers should be redirected to the link they used to sign up.

Description

New Portal-only customers will be redirected to the portal link (using the sign-up link in the verification email) when provided with a portal group,
request form, or portal article link to sign up.

It is quite interesting that upon clicking a link, all users land on a URL like https://domain/servicedesk/customer/portal/# /user/login?destination=portal%2F4%2Farticle%2F86179841 which clearly has parameter referencing the destination and that is how users will land on the same page in all other scenarios (except new portal-only customers). However, the JWT parameter in email verification for new portal-only customer does not respect this parameter.

Steps to Reproduce

1. Copy a request form link (e.g. https://domain/servicedesk/customer/portal/#/group/#/create/#) and send it to the (portal-only) customer that does not have an account
2. The (portal-only) customer opens the link and signs up with a password
3. Atlassian will send an email to finish sign up
4. The (portal-only) customer clicks on the link in the email, enters their full name and password, then selects Finish button
5. The user will land on https://domain/servicedesk/customer/portal/6. Notice that the URL the (portal-only) customer is redirect to is missing the request form part (i.e "group/#/create/#" in the URL

Expected Results

The new (portal-only) customer is redirected to the request form URL (i.e. https://domain/servicedesk/customer/portal/#/group/#/create/#) after signing up to the portal. 

Actual Results

The new (portal-only) customer is redirected to the portal URL (i.e. https://domain/servicedesk/customer/portal/#/) after signing up to the portal.