Also cleaned up logic for whether we need to poll for events:
- We need to periodically poll for joysticks to handle hotplug.
- We need to frequently poll for joysticks and sensors when they're open so their state can be updated
Instead of indexing into an internal list of devices which requires locking, we return a list of device IDs which can then be queried individually.
Reference: https://github.com/libsdl-org/SDL/issues/6889
Sam Lantinga