Also return RGB color from `useContrastText`

### Description

It would be nice if `useContrastText` could return something like `{ color, colorRgb }` so that it can be used for non native-base components as well.

### Problem Statement

Currently `useContrastText` returns `lightText` or `darkText `, which is only useable for native base components. Without an extra roundtrip to `useTheme`, there's no way to use these values.

### Proposed Solution or API

Either return an object or an array with additional values, such as `colorRGB`.

Another solution would be to have the contrasted text values already in the theme (MUI does this for instance).

### Alternatives

_No response_

### Additional Information

_No response_