[native] Introduce ColorSelector component

Summary:
Part of the first step in redesigning the ColorPicker component on native to match the ColorSelector component on web introduced by @atul. Depends on D3790

ColorSelector is a new component that will work with ColorSelectorButton to replace ColorPicker on native. This diff handles color layout, and adding onPress handling and active state functionality will be applied in later diffs.

See the full plan for the ColorPicker redesign in this Linear issue.

Test Plan:
Tested on iOS 15.4 and works as expected:

Reviewers: atul

Reviewed By: atul

Subscribers: ashoat, palys-swm, Adrian, karol-bisztyga, atul, benschac

Differential Revision: https://phabricator.ashoat.com/D3798