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/plugin_status.go

@@ -0,0 +1,27 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+const (
+	PluginStateNotRunning          = 0
+	PluginStateStarting            = 1 // unused by server
+	PluginStateRunning             = 2
+	PluginStateFailedToStart       = 3
+	PluginStateFailedToStayRunning = 4
+	PluginStateStopping            = 5 // unused by server
+)
+
+// PluginStatus provides a cluster-aware view of installed plugins.
+type PluginStatus struct {
+	PluginId    string `json:"plugin_id"`
+	ClusterId   string `json:"cluster_id"`
+	PluginPath  string `json:"plugin_path"`
+	State       int    `json:"state"`
+	Error       string `json:"error"`
+	Name        string `json:"name"`
+	Description string `json:"description"`
+	Version     string `json:"version"`
+}
+
+type PluginStatuses []*PluginStatus