MM-8853: Adding MANAGE_EMOJIS and MANAGE_OTHERS_EMOJIS permissions (#8860)

* MM-8853: Adding MANAGE_EMOJIS and MANAGE_OTHERS_EMOJIS permissions

* MM-8853: Removing unnecesary emoji enterprise feature

* Create emojis migration

* Adding MANAGE_EMOJIS and MANAGE_OTHERS_EMOJIS always to system admins

* Simplifing permissions checks

* Revert "Simplifing permissions checks"

This reverts commit e2cafc1905fc9e20125dd9a1552d2d0c7340ae59.

einterfaces/emoji.go

@@ -1,12 +0,0 @@
-// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
-// See License.txt for license information.
-
-package einterfaces
-
-import (
-	"github.com/mattermost/mattermost-server/model"
-)
-
-type EmojiInterface interface {
-	CanUserCreateEmoji(string, []*model.TeamMember) bool
-}