Device Components.

The purpose of this feature is to provide a framework for discovery modules to store
information in the database, without needing to add new tables for each feature.

This Feature provides:
- A database structure to store data.
- An API to store and retrieve data from the database.
- Integration to the LibreNMS APIv0.
- Ability to disable/ignore components.
- Default alerting rules.

- The API returns $COMPONENT[$device_id][$component_id] to allow pulling of data for multiple devices.
  The intent is to be able to create 'Applications' the consolidate data from applications covering multiple devices.
- Added some developer documentation

html/api_v0.php

@@ -49,6 +49,8 @@ $app->group(
                         // api/v0/devices/$hostname/graphs
                         $app->get('/:hostname/ports', 'authToken', 'get_port_graphs')->name('get_port_graphs');
                         // api/v0/devices/$hostname/ports
+                        $app->get('/:hostname/components', 'authToken', 'get_components')->name('get_components');
+                        // api/v0/devices/$hostname/components
                         $app->get('/:hostname/:type', 'authToken', 'get_graph_generic_by_hostname')->name('get_graph_generic_by_hostname');
                         // api/v0/devices/$hostname/$type
                         $app->get('/:hostname/ports/:ifname', 'authToken', 'get_port_stats_by_port_hostname')->name('get_port_stats_by_port_hostname');