[MM-13840] Change eMail as a post-verification action (#10253)

* Change eMail as a post-verification action

* Fix broken test

* comment for special behavior, tests

* govet

* Check for already existent eMails when require email verification is turned on before accepting update

cmd/mattermost/commands/user.go

@@ -693,7 +693,7 @@ func verifyUserCmdF(command *cobra.Command, args []string) error {
 			CommandPrintErrorln("Unable to find user '" + args[i] + "'")
 			continue
 		}
-		if cresult := <-a.Srv.Store.User().VerifyEmail(user.Id); cresult.Err != nil {
+		if cresult := <-a.Srv.Store.User().VerifyEmail(user.Id, user.Email); cresult.Err != nil {
 			CommandPrintErrorln("Unable to verify '" + args[i] + "' email. Error: " + cresult.Err.Error())
 		}
 	}