get_data_dir
Description:
Gets the data dir of the plugin.
The module data directory is the directory where a plugin should find its runtime data. This is not a value read from the [struct@GLib.KeyFile] , but rather a value provided by the [class@Engine], depending on where the plugin file was found.
Parameters:
| this | A PluginInfo. | 
Returns:
| the plugin's data dir. |