add email functionality to the add new user form

[thomasbeaudry]

Current Implementation and Limitations

Currently we can create users, and manually copy and paste the username and password that we selected and then email the user this info. It would be great if this could automatically be emailed to the new user instead with a template message.

Associated Application Components

Client, Server

Proposed Solution

Currently the page looks like this:

We should create a second button right next to submit (and make both buttons half the width of the original submit button). We should rename the "submit" button to "create" or "create new user" and the other new button should be "create & email user". Feel free to come up with better buttons name.

In order for this to work, we are going to have to have a place to configure the mail server, and a place to set the template message that gets emailed to the user. This could be done via the .env file (or a seperate .env file) but this isn't ideal since it needs to be documented somewhere / the admins need to know they have to set this. Ideally it would be better if we have a front-end place to do it. 1 day we should probably have an admin panel, but for now we can use the app settings page:

This page can have the necessary fields to confige the mail server:
SMTP Port
SMTP Host
SMTP username
SMTP password
From: email
To: email
(We could also send emails via the API key, but you'd probably need to set a toggle/drop down if you want to include this way)

and a template email message. The template message should be in a pre-populated textbox that someone can edit.

Estimated Difficulty

Medium

Priority

Medium