Add save_position

[hazlamshamin]

For PLR move_channel_xyz in opentrons_backend, this is needed to first query the current position of the pipette (any channel 0 or 1)

[rickwierenga]

What is position id?

[hazlamshamin]

Just "an ID to reference this position in subsequent requests", eg if needed to be saved and referenced. this is the case in opentrons/api/src/opentrons/protocol_engine/commands/save_position.py, so just matching it.

[hazlamshamin]

can we merge this yet?

[rickwierenga]

thanks for the reminder

so it can optionally save the position, but in any case it returns the current coordinates? that's a good find!

[hazlamshamin]

yeah it does. that's the main reason i wanna add it actually. have also used it in my test case in the new move_channel_xyz i just pushed PR yesterday in PLR for the opentrons_backend

PyLabRobot/pylabrobot#767

[rickwierenga]

got it, thanks!