GAWB-3261: Calling POST /register/profile with a plus in contactEmail returns 400

[irosenbe]

Acceptance Criteria:
An email with a plus in it in the contact. Email field can be registered successfully.

Description:
Reported by AoU folks. They tried to register jmandel+aou-rw-stable@verily.com as a contact email and it fails.

Plus is a valid character in email addresses. We should be OK with it.

Implementation notes:
This could be a problem with orch's email validation:
https://github.com/broadinstitute/firecloud-orchestration/blob/develop/src/main/scala/org/broadinstitute/dsde/firecloud/model/Profile.scala#L112

NB: this bug affects users who are updating their profile as well as newly-registering users. Therefore as a developer, you can test/reproduce this simply by updating your profile.

Testing note: API level testing, no need for selenium

Link to GAWB ticket: https://broadinstitute.atlassian.net/browse/GAWB-3261