Components: Fixing Text Contrast for Dark Mode

[im3dabasia]

Part of: #66454
Comment: #66454 (comment)

Work in progress

What?

Fixes the components labels/headings in the dark mode

Testing Instructions

1. Run npm run storybook:dev.
2. Open Storybook at http://localhost:50240/.
3. Verify that the following components work well in dark mode, and ensure that all other modes continue to function as they did previously.

Screenshots or screencast

AnglePickerControl

Before	After

CustomGradientPicker

Before	After

FocalPointPicker

Before	After

GradientPicker

Before	After

InputControl

Before	After

NumberControl

Before	After

PaletteEdit

Before	After

QueryControl

Before	After

SelectControl

Before	After

TreeSelect

Before	After

UnitControl

Before	After

[github-actions]

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Co-authored-by: im3dabasia <[email protected]>
Co-authored-by: tyxla <[email protected]>

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[im3dabasia]

Hi @t-hamano, when you have a moment, please review my PR addressing labels and headings visibility in dark mode, extracted from this comment.

[tyxla]

Looks and works great! 👍 ✅

I've fixed a few snapshot and unit tests that needed to be updated, and will ship it shortly. 🚢

Thanks for your contribution @im3dabasia 🙌