* feat(html-view): Additional properties for HtmlView component
- Allow to set text color with `color` CSS property.
- Allow to set link color with `link-color` CSS property.
- Allow to set font attributes with `font-family` and `font-size` CSS properties.
- Make text selectable on Android by default (for consistency with IOS).
- Remove extra padding on IOS.
* refactor: Move uiColorToHex function to nativescript-core/color module
* test: adding test for new HtmlView css properties
Co-authored-by: Vasil Trifonov <v.trifonov@gmail.com>