Add recipient user token

Sorry but this assumes the recipient email is drawn from a user.
The module supports any email field, not just users.

I don't see how we can support this.

The idea is to add additional tokens, such as the user's information, to enhance the template with supportive details, but only if the email was related to an existing user. If these tokens are not available, they will not impact the template's functionality.

This approach can be useful for incorporating more personalized information about the recipient in the template, such as "Dear [recipient's first name]."

I think we'd need to convey to the user that the tokens were it weren't available
That would likely require extra information on the plugins

I've updated the description of the available token for the email body field. Also, I added the user tokens to the tokens tree.