feat: Add template string fallback attributes

[camdecoster]

Description

Add template string fallback attributes.

Closes #7564
Closes #7565

Changes

• Lints/formats files updated in this PR
• Adds hovertemplatefallback and texttemplatefallback attributes
• Adds helper functions to include these attributes
• Updates templateFormatString (and derived functions) to pass fallback value in, use in case of missing variable
• Updates tests, baseline images per above changes

Demo video or screenshots

Before	After

Testing

• Be on master
• Load the following mock using plotly.js DevTools:

  {
    "data": [
      {
      "hovertemplate": "Time: %{x}<br>User: %{y}<br>Usage: $%{z:.2f}<extra></extra>",
      "hovertemplatefallback": "Citra Hops",
      "showscale": true,
      "z": {
        "dtype": "f8",
        "bdata": "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",
        "shape": "10, 12"
      },
      "type": "heatmap"
      }
    ]
  }

• Hover over a blank square and note that the 'Usage' line contains the format specifier
• Switch to this branch
• Reload the same mock
• Hover over a blank square and note that the 'Usage' line contains the fallback value

Notes

• The default fallback value is an empty string: ''
• The linting/formatting changes make it hard to review this PR. I'd suggest looking at individual commits. For the most part, these touch different files.

TODO

• Add draftlog
• Add/update tests for fallback value