generate_missing_thumbnails_async

async omni.kit.widget.filebrowser.thumbnails.generate_missing_thumbnails_async(missing_thumbnails: List[str])

When missing thumbnails are discovered, send an event to have them generated. The generator service is a separate process. Once generated, a reciprocal event is sent to update the UI. The flow is diagramed below:

+-------------------------------+                        +------------------------------+
|         Filebrowser           |                        |                              |
|  +-------------------------+  |   Missing thumbnails   |                              |
|  |                         |  |        event           |                              |
|  |       update_grid       +--------------------------->     Thumbnail generator      |
|  |                         |  |                        |          service             |
|  +-------------------------+  |                        |                              |
|  +-------------------------+  |      Thumbnails        |                              |
|  |                         |  |   generated event      |                              |
|  |    update_cards_on      <---------------------------+                              |
|  |  thumbnails_generated   |  |                        |                              |
|  +-------------------------+  |                        |                              |
|                               |                        |                              |
+-------------------------------+                        +------------------------------+