feat(Registration): Email verification

[Aaron-Detre]

Changes

• Added two new fields to teacher_user_details table in database: isVerified and verificationCode.
• After registering a new teacher account (not Google or Microsoft), an email is sent containing a link to verify your new account.
• Added endpoint to check whether user is verified (only relevant for teachers).
• Added endpoint to verify a teacher account, send them the welcome email, and then redirect them to the login page.
• Added endpoint to resend the verification email.
• Moved mail related methods into MailService.

Test

• Test with feat(Registration): Email verification WISE-Client#2328
• ALTER TABLE teacher_user_details
  ADD COLUMN isVerified BIT(1) NOT NULL DEFAULT TRUE,
  ADD COLUMN verificationCode VARCHAR(255) NULL;
• Nothing should change when creating a student account or a teacher account with Google or Microsoft.
• Creating a new teacher account with email should send a verification email.
• Clicking the link in that email should trigger a welcome email to be sent and you should be redirected to the WISE login page.
• Clicking to resend the verification email should send the verification email to your account again.

Other

• Three tests that have been around for years were failing. I checked it out, but they all seemed to have actually been written incorrectly. I changed them in the latest commit, but I'm not sure why they only started causing issues now. I guess it's possible that they were written correctly before and I've just changed them to be incorrect, but I don't see how that could be the case.