[MM-43337] Updating email templates for trial will end and trial ended emails (#19976)

* Updating email templates for trial will end and trial will end emails

* put back variable

* Rebuilding

* fix tests

* Updates

* [MM-43339] Add Cloud Subscription Upgrade Confirmation Email (#19989)

* Add Cloud Upgrade Confirmation email

* Updates

* String change

* i18n-extract

* Updates

* make email-mocks

* Appease linter

* Add a test

* GMAIL NEVER RENDERS RIGHT

* Important EVERYWHERE because gmail just cant deal

* l

* Last one

* Update image

* Update tests

* Fix tests

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/cloud.go

@@ -6,11 +6,12 @@ package model
 import "strings"
 
 const (
-	EventTypeFailedPayment         = "failed-payment"
-	EventTypeFailedPaymentNoCard   = "failed-payment-no-card"
-	EventTypeSendAdminWelcomeEmail = "send-admin-welcome-email"
-	EventTypeTrialWillEnd          = "trial-will-end"
-	EventTypeTrialEnded            = "trial-ended"
+	EventTypeFailedPayment                = "failed-payment"
+	EventTypeFailedPaymentNoCard          = "failed-payment-no-card"
+	EventTypeSendAdminWelcomeEmail        = "send-admin-welcome-email"
+	EventTypeSendUpgradeConfirmationEmail = "send-upgrade-confirmation-email"
+	EventTypeTrialWillEnd                 = "trial-will-end"
+	EventTypeTrialEnded                   = "trial-ended"
 )
 
 var MockCWS string