Fix/839 unit magic for low and high emissions

[omgMath]

Fixes #839

• Instead of using multiple units, we use some logic to determine the unit (g, kg, t) to use and adjust the label accordingly.
  To not mess with the original data we decided to store the emissions column in different units (emissions_in_g, emissions_in_t).
• Unit tests are written and run successfully.
• Added a label "Entry" for the unlabeled index on the x-axis.
• Auto reformat for some files.

[Copilot]

Pull Request Overview

Improves emissions unit handling by selecting an appropriate unit (g, kg, t), extending the DataFrame with converted columns, and updating the bar chart to use dynamic unit labels and a custom “Entry” x-axis label.

• Introduces get_emissions_unit and extends_emissions_units for unit selection and conversion
• Updates bar chart generation to pick the correct emissions column and add labels for all units
• Adds unit tests for the new utility functions

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

File	Description
tests/test_viz_units.py	New tests for unit determination and DataFrame extension
tests/test_viz_data.py	Minor formatting fix to parameter list
codecarbon/viz/units.py	Implements emission unit logic and adds conversion columns
codecarbon/viz/components.py	Switches bar chart to dynamic emissions column and updates labels

[benoit-cty]

Thank you for contributing.

If you want to fix the pre-commit error, you could look at https://github.com/mlco2/codecarbon/blob/master/CONTRIBUTING.md#coding-style--linting to install it locally.

[omgMath]

@benoit-cty Anything blocking this PR?

[benoit-cty]

Hello,

Sorry for the delay. I've updated the dependencies to use a modern version of Dash.

I've also updated the documentation.

Here is a sample of the graph:

To be honest we were thinking about deleting the local dashboard as we have made an online one at https://dashboard.codecarbon.io/

[benoit-cty]

I have to fix some failing tests, I don't know how they append to fail in this PR.