Add MPLS Support (#10263)

* WIP - Add MPLS Support
This introduce the generic MPLS support
- New database tables for MPLS LSPs
- actually discovery and polling on NOKIA SR OS (Timetra) devices
- new routing->MPLS HTML pages

- ToDo MPLS LSP paths table and views
Suggestions and improvements are welcome

* add db schema

* some fixes

* add path table, discovery and polling

* add path views

* add test data

* Convert MPLS module to new style
Implement a SyncsModels trait to simplify code a lot

* abs() for negative value from snmp (bug?), test data

* fix db schema

* Fix up test data, remove uneeded data in json

* fix whitespace

LibreNMS/Util/ModuleTestHelper.php

@@ -56,6 +56,7 @@ class ModuleTestHelper
         'fdb-table' => ['ports', 'vlans', 'fdb-table'],
         'vlans' => ['ports', 'vlans'],
         'vrf' => ['ports', 'vrf'],
+        'mpls' => ['ports', 'vrf', 'mpls'],
         'nac' => ['ports', 'nac'],
         'cisco-mac-accounting' => ['ports', 'cisco-mac-accounting'],
     ];