[JMAP] Send: EmailSubmission/create (user email)

Why

As a user, I want to send an existing email.

How

Implement `EmailSubmission/set create`

[[ "EmailSubmission/set", {
  "accountId": "ue411d190",
  "create": {
    "k1490": {
      "emailId": "M7f6ed5bcfd7e2604d1753f6c",
      "envelope": {
        "mailFrom": {
          "email": "john@example.com",
          "parameters": null
        },
       "rcptTo": [{
         "email": "jane@example.com",
         "parameters": null
       }]
     }
   }
 }
}, "0" ]]

Note: IdentityId is not specified.
Note: EmailParameters should be left null.

Creating an EmailSubmission gets the given email being sent.

Restrictions:

• The FROM field of the envelope needs to belong to the sender. In which case it fails with `forbiddenMailFrom`.
• The FROM field of the EML needs to belong to the sender. In which case it fails with `forbiddenFrom`.

Definition of Done

Write a unit test demonstrating you can send emails.