#80 Add support for the Sparkfun DE2120 barcode reader

[sighmon]

Resolves #80

We'd like to add support for scanning barcodes or QR codes as a lens tap to support printed tickets.

Acceptance Criteria

• Add support for the Sparkfun DE2120 barcode reader

Relevant design files

• None

Testing instructions

1. Set your READER_MODEL to Sparkfun DE2120 in Balena environment variables
2. Set your TARGET_API_ENDPOINT to your local XOS: http://192.168.x.x:8000/api/
3. Add a barcode as a UID for a new Lens to XOS: http://localhost:8000/admin/exhibitions/lens/add/
4. Add your Raspberry Pi to e__tap-reader-pi-4
5. Plug in the USB barcode reader
6. Try scanning a barcode and note it appears in XOS: http://localhost:8000/lens/
7. Note you can turn the scanner on/off using the Lights API

# Turn off reader
curl --location 'http://192.168.1.101:8082/api/lights/' \
--header 'Content-Type: application/json' \
--data '{
    "rgb_value": [0,0,0],
    "ramp_time": 0.5,
    "cross_fade": 1.0
}'

# Turn on reader
curl --location 'http://192.168.1.101:8082/api/lights/' \
--header 'Content-Type: application/json' \
--data '{
    "rgb_value": [0,0,0],
    "ramp_time": 0.5,
    "cross_fade": 0
}'

[rubyquaildesign]

Approving conditionally on this branch working with the barcode reader, which I believe was successful with Jeff