We use it to open endpoints as they are used. Fetching the descriptor
as needed can cause issues with devices that we're expecting a control
packet while another transaction was ongoing. Specifically, a usb
thumb drive didn't expect a control transaction while doing a SCSI
transaction.
This PR also aborts transactions on timeout or ctrl-c interrupt. It
doesn't always recover though...
This allows you to list and explore connected USB devices. It
only stubs out the methods to communicate to endpoints. That will
come in a follow up once TinyUSB has it. (It's in progress.)
Related to #5986
