Components: apply design feedback to g2 ColorPicker

[ciampo]

Part of #34284

Why

The ColorPicker component has been recently added to the Gutenberg repository and needs to go through a few design tweaks

What

Mostly design refinements that were missed in the first iteration working on the component

A/C

• The white border on the circle controls looks too wide in the storybook compared to the design
• The input padding is off, not sure if this is something we need to affect on all inputs or we can just start with the input + slider case.
• spacing between slider and input is off
• use the new settings icon from wp/icons (requires Icons: update settings icon to latest version #34288)
• the color format dropdown should be rendered without borders, - [ ] not sure how we want to handle this at the component level since it should be an optional thing used rarely
• the slider circular handle is too big compared to designs

[mtias]

Moving these directly to the tracking issue.