Add ability to select imap and smtp access for mailcow users

variables.tf

@@ -173,6 +173,8 @@ variable "services" {
     s3_buckets = optional(list(string))
     database = bool
     mail = optional(string)
+    mail_smtp = optional(bool, true)
+    mail_imap = optional(bool, false)
   }))
 }