[MM-33198] - Portal: Send admin welcome email after the installation is complete (#17043)

* [MM-33198] - Portal: Send admin welcome email after the installation is complete

* Send cloud welcome email

* Feedback impl-2

* Fix template

* Temp undo

* Update

* make i18n-extract

* Translations

* Feedback impl-3

* More template fixes

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

model/user.go

@@ -98,6 +98,7 @@ type User struct {
 	BotLastIconUpdate      int64     `db:"-" json:"bot_last_icon_update,omitempty"`
 	TermsOfServiceId       string    `db:"-" json:"terms_of_service_id,omitempty"`
 	TermsOfServiceCreateAt int64     `db:"-" json:"terms_of_service_create_at,omitempty"`
+	DisableWelcomeEmail    bool      `db:"-" json:"disable_welcome_email"`
 }
 
 //msgp UserMap