Refactor bf2raw command to be central/common function

[annshress]

Addresses #316

Changes

• Move bioformats2raw command in neuroglancer.py (non-task, so it can be mocked easily)
• Updated pytest github workflow so that .env file exists
• Breaking changes: "Nothing"❗️

This PR doesn't introduce any:

• Binary files
• Temporary files, auto-generated files
• Secret keys
• Local debugging print statements
• Unwanted comments (e.g: # Gets user from environment for code os.environ['user'] )

This PR contains valid:

• tests

[github-actions]

Coverage report

The coverage rate went from 26.89% to 64.77% ⬆️
The branch rate is 47%.

24.13% of new lines are covered.

Diff Coverage details (click to unfold)

em_workflows/constants.py

100% of new lines are covered (100% of the complete file).

em_workflows/czi/constants.py

100% of new lines are covered (100% of the complete file).

em_workflows/czi/flow.py

33.33% of new lines are covered (39.79% of the complete file).
Missing lines: 82, 83

em_workflows/utils/neuroglancer.py

20% of new lines are covered (19.14% of the complete file).
Missing lines: 10, 11, 12, 34, 35, 51, 52, 53, 54, 55, 56, 63, 64, 65, 67, 68, 70, 74, 75, 77