[feature request] Automatically send email when new user account is created

[massey21]

As we transition user onboarding to NEMO, our staff asked if it would be possible to have NEMO automatically send a templated email upon user account creation. This both notifies the user that their account is active, and it also directs them to a page that details the onboarding steps and all the forms/documents they need.

In its simplest form, this would only need to send to the user, but a lower priority 'stretch goal' might be to also send to a list defined under Customization --> Email Addresses. This list could be the User Office list, or for even more flexibility, another (new) Onboarding alias. Adding a second alias would allow (by leaving it empty) labs to not cc additional people, but I can appreciate that in many facilities this additional alias might seem redundant. Notifying this additional person or group of people that the account was created may trigger additional actions in the background.

[arcturusannamalai]

Django provides send email facility but this has to be setup properly.