[rfr] Send user ID to sendgrid, for optional use by email templates

[abought]

Ticket: https://openscience.atlassian.net/browse/LEI-237

Purpose

Allow password reset / new user emails from JamDB to reference the user associated with this action.

Previously, the only variable available to sendgrid was the token.

Checklist

Behavior:

• Include correct user id (eg "abought1") in email templates
• Sendgrid can act on this substitution in templates, where appropriate
• Sendgrid can ignore unused substitutions, where appropriate
• Verify emails are correctly formatted and display values as expected

Documentation

• Get unit tests passing
• Document how to contribute and how to run tests

How to test this

• Create a JamDB project with an accounts collection. Add the following attributes to the collection to enable login and email behaviors (providing your own sendgrid key and template ID as appropriate)

    attrs: {
        ...
      schema: {
        "type": "jsonschema",
        "schema": {
          "type": "object",
          "required": [
            "password"
          ],
          "id": "/",
          "properties": {
            "password": {
              "id": "password",
              "pattern": "^\\$2b\\$1[0-3]\\$\\S{53}$",
              "type": "string"
            }
          }
        }
      },
...
        plugins: {
            user: {
              fromEmail: "spammer-catapult@nospam.com",
              sendgridKey: "SG.DangerWillRobinson",
              createdIsOwner: true,
              template: "a-b-c-d-e"
            }
      },
    }

A sample SendGrid template would be:

Hi, :unspecifiedsubst ,

Your user id is:  :user

You have a token, but this email doesn't tell you what it is. In conclusion, yay dinosaurs!

Then send a password request- if you use Lookit, the app will do this for you. The email should contain the user ID ("abought1") for the relevant account in place of the :user field.