Allow OKlab / OKlch as output format

## Description

In the current version of the Web Tool I can NOT use neither oklab nor oklch as output option in use "Use" area. Only the older versions lab and lch are available.

## Why do you need this feature?

The ok version fix some errors of the none ok version.

## Additional context

Both ok color models should be available in the whole web tool and also in the npm version as an export / output option.

Start by locating the Web Tool's "Use" area and the npm version's export/output entry points. Add OKlab and OKlch as available output options in both contexts, and verify that both color models are exposed throughout the Web Tool and npm version.

Written by the indexing model from the issue text.