Boards data retention (#19262)

* add Boards to DataRetention, add hook for data retention

* remove replaces

* update hook to remove parameter

* add boards data retention to telemetry

* fix unit test

* update test, update hooks

* update RunDataRetention server version

* put behind a feature flag

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/plugin_hooks_test.go

@@ -1215,3 +1215,47 @@ func TestHookReactionHasBeenRemoved(t *testing.T) {
 
 	require.Nil(t, err)
 }
+
+func TestHookRunDataRetention(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	tearDown, pluginIDs, _ := SetAppEnvironmentWithPlugins(t,
+		[]string{
+			`
+		package main
+
+		import (
+			"github.com/mattermost/mattermost-server/v6/plugin"
+		)
+
+		type MyPlugin struct {
+			plugin.MattermostPlugin
+		}
+
+		func (p *MyPlugin) RunDataRetention(nowMillis, batchSize int64) (int64, error){
+			return 100, nil
+		}
+
+		func main() {
+			plugin.ClientMain(&MyPlugin{})
+		}
+	`}, th.App, th.NewPluginAPI)
+	defer tearDown()
+
+	require.Len(t, pluginIDs, 1)
+	pluginID := pluginIDs[0]
+
+	require.True(t, th.App.GetPluginsEnvironment().IsActive(pluginID))
+
+	hookCalled := false
+	th.App.GetPluginsEnvironment().RunMultiPluginHook(func(hooks plugin.Hooks) bool {
+		n, _ := hooks.RunDataRetention(0, 0)
+		// Ensure return it correct
+		assert.Equal(t, int64(100), n)
+		hookCalled = true
+		return hookCalled
+	}, plugin.RunDataRetentionID)
+
+	require.True(t, hookCalled)
+}