Send new users (added by site admin) the password reset URL over email

Created by: sqs

As a site admin, I want new users (added by me in the site admin area) to receive an email with a URL they visit to create a password, instead of me (the site admin) getting the URL to copy-paste to them. This would make it faster to add many users (because I wouldn't need to open a private chat with each user and paste them a link). It would also reduce the likelihood of me making a mistake and sending a URL to the wrong user. (This would only occur if the site config email.smtp property is set. If not, copy-pasting the URL is OK.)

This is low priority because site admins who need to add many users should use an external auth provider (SSO), or they can use the GraphQL API if SSO is not an option.

Requested by @P3GLEG