feat(pygal): implement heatmap-interactive (#3328)

## Implementation: `heatmap-interactive` - pygal

Implements the **pygal** version of `heatmap-interactive`.

**File:** `plots/heatmap-interactive/implementations/pygal.py`

**Parent Issue:** #3289

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:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/pyplots/actions/runs/20822856761)*

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