Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/app/platform/errors.go

@@ -0,0 +1,24 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package platform
+
+import "errors"
+
+var (
+	AcceptedDomainError       = errors.New("the email provided does not belong to an accepted domain")
+	VerifyUserError           = errors.New("could not update verify email field")
+	UserCountError            = errors.New("could not get the total number of the users.")
+	UserCreationDisabledError = errors.New("user creation is not allowed")
+	UserStoreIsEmptyError     = errors.New("could not check if the user store is empty")
+
+	GetTokenError            = errors.New("could not get token")
+	GetSessionError          = errors.New("could not get session")
+	DeleteTokenError         = errors.New("could not delete token")
+	DeleteSessionError       = errors.New("could not delete session")
+	DeleteAllAccessDataError = errors.New("could not delete all access data")
+
+	DefaultFontError   = errors.New("could not get default font")
+	UserInitialsError  = errors.New("could not get user initials")
+	ImageEncodingError = errors.New("could not encode image")
+)