Add possibility to send e-mails using Commerce Email module

Problem/Motivation

I'm suggesting instead of the custom e-mail sending implementation, emit an event to which Commerce Email module can subscribe. That way we can set up the e-mail text as we need, translate it, and unify the way we set up e-mails to the store in one place. No need to mess around with templates.

To build the e-mail text there, we need EmaiEvent plugin, tokens for everything that is now passed to the mail twig template.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes