[user_accounts] Examiners with same name removed from table

[CamilleBeau]

Describe the bug
If a new user is set as an examiner who has the same first and last name as an examiner that already exists, the pre-existing examiner is removed from the examiners table, replaced by the new one.

To Reproduce
Steps to reproduce the behavior (attach screenshots if applicable):

1. Create a new user with the exact same first / last name as a pre-existing examiner, and set this user as an examiner
2. look at the examiners table and notice that the first examiner is no longer there, but the newly created examiner is.

[ridz1208]

@jesscall don't start working on this just yet, let's discuss it first.

[CamilleBeau]

Resolved