v8.0 module release (#22975)

https://mattermost.atlassian.net/browse/MM-52079

```release-note
We upgrade the module version to 8.0. The new module path is github.com/mattermost-server/server/v8.
```


Co-authored-by: Doug Lauder <wiggin77@warpmail.net>

server/model/push_response.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+const (
+	PushStatus         = "status"
+	PushStatusOk       = "OK"
+	PushStatusFail     = "FAIL"
+	PushStatusRemove   = "REMOVE"
+	PushStatusErrorMsg = "error"
+)
+
+type PushResponse map[string]string
+
+func NewOkPushResponse() PushResponse {
+	m := make(map[string]string)
+	m[PushStatus] = PushStatusOk
+	return m
+}
+
+func NewRemovePushResponse() PushResponse {
+	m := make(map[string]string)
+	m[PushStatus] = PushStatusRemove
+	return m
+}
+
+func NewErrorPushResponse(message string) PushResponse {
+	m := make(map[string]string)
+	m[PushStatus] = PushStatusFail
+	m[PushStatusErrorMsg] = message
+	return m
+}