MM-53924 - Implement push notifications plugin hook and plugin api method (#24350)

* Revert "MM-52804 - Implement SendPushNotification plugin api method (#24273)"

This reverts commit 8418eefb75.

* Revert "MM-53924 - Implement NotificationWillBePushed plugin hook (#24263)"

This reverts commit f13a531bca.

* implement NotificationWillBePushed plugin hook

* implement SendPushNotification plugin api method

* move where we're setting post and channel type

* fix comment

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/plugin/api_timer_layer_generated.go

@@ -1267,9 +1267,9 @@ func (api *apiTimerLayer) GetUploadSession(uploadID string) (*model.UploadSessio
 	return _returnsA, _returnsB
 }
 
-func (api *apiTimerLayer) SendPluginPushNotification(notification *model.PluginPushNotification) error {
+func (api *apiTimerLayer) SendPushNotification(notification *model.PushNotification, userID string) *model.AppError {
 	startTime := timePkg.Now()
-	_returnsA := api.apiImpl.SendPluginPushNotification(notification)
-	api.recordTime(startTime, "SendPluginPushNotification", _returnsA == nil)
+	_returnsA := api.apiImpl.SendPushNotification(notification, userID)
+	api.recordTime(startTime, "SendPushNotification", _returnsA == nil)
 	return _returnsA
 }