3.x Update `EmailTrait`

[AlexSkrypnyk]

When I enable the test email system
When I disable the test email system
When I clear the test email system queue
Then an email should be sent to the :address
Then no emails should be sent
Then no emails should be sent to the :address
Then the email header :header should contain:
Then the email header :header should be:
Then an email should be sent to the address :address with the content:
Then an email should be sent to the address :address with the content containing:
Then an email should be sent to the address :address with the content not containing:
Then an email should not be sent to the address :address with the content:
Then an email should not be sent to the address :address with the content containing:
Then the email field :field should contain:
Then the email field :field should be:
Then the email field :field should not contain:
Then the email field :field should not be:
When I follow link number :link_number in the email with the subject :subject
When I follow link number :link_number in the email with the subject containing :subject
Then the file :file_name should be attached to the email with the subject :subject
Then the file :file_name should be attached to the email with the subject containing :subject