* fix inventory plugin source caching
- avoid caching invetnory sources in loader in base
- same fix for yaml plugin
- idem for 'auto' plugin
fixes#37162
* fix mock dataloader func sig
* Automatically loads and executes an inventory plugin specified by a standard YAML inventory config file containing a `plugin` key at its root.
* Moved inventory PluginLoader to a shared global instance.
Pierre-Louis Bonicoli
Zhikang Zhang
Rémy Léone
Brian Coca
Matt Davis