Revert "MM-27147 - /cloud api endpoints (#15428)" (#15615)

This reverts commit 88aed7ec9e.

einterfaces/cloud.go

@@ -1,15 +0,0 @@
-// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
-// See LICENSE.txt for license information.
-
-package einterfaces
-
-import (
-	"github.com/mattermost/mattermost-server/v5/model"
-)
-
-type CloudInterface interface {
-	GetCloudProducts() ([]*model.Product, *model.AppError)
-
-	CreateCustomerPayment() (*model.StripeSetupIntent, *model.AppError)
-	ConfirmCustomerPayment(*model.ConfirmPaymentMethodRequest) *model.AppError
-}