Fix #32235.

Per discussion points in #32235

• Color value ranges. Now we only expose float number between 0...1 .
• Color.fromHex, Color.fromHSL are removed from the API.
• Color Insertion. This is not done, but it's not a blocker to the API finalization.

With the new API,

• The title of Color Picker only shows four color format, RGB, HEX, HSL, HSA, which are representatives of RGB color model. When users click on it, we iterate through them.
• When users move the cursor inside the saturation box, we only make updates to the document when mouse up.
• Since we only make changes when the color is finalized (mouse up), we ask the provider for string representative of selected color. We don't flood the extensions of both API call or content change.
• Extensions format the color per Color Format users select in the color picker.

For now, the four formats are good enough as long as we are only targeting RGB color model. If there is other feature request, we need to update both provideColorRange and resolveColor as the color can no longer be represented as RGB. cc @joaomoreno @jrieken