bug: API log files no longer include the slot number where a piece of labware is located

[ethanfjones-zz]

Overview

API log file commands now include alphanumeric characters instead of the numbered slot where a piece of labware is located.

Steps to reproduce

1. Run a protocol with an API version of 2.9 on an OT-2 with a software version of 4.1.1 or above
2. Download and review the API log files

Current behavior

An aspirate step in the API log files now looks like:

InstrumentContext.aspirate: {'volume': 100, 'location': <opentrons.types.Location object at 0x70f62dd0>, 'rate': 1.0}

Expected behavior

An aspirate step in the API log files should look like:

InstrumentContext.aspirate: {'volume': 100, 'location': Location(point=Point(x=63.88, y=42.74, z=5.550000000000001), labware=A1 of rez on 1), 'rate': 1.0}