Color picker does no longer accept shortened RGB values

[christianlupus]

The color picker component NcColorPicker does no longer accept colors in the shortened format (like #ABC for #AABBCC) as colors for the color palette. This due to the implementation in hexToRGB that assumes a format with 6 digits.

This should either be fixed or the documentation should clearly state that only full hex RGB values are allowed.

[Antreesy]

Should work in theory from upstream library, but it's not:
https://github.com/xiaokaike/vue-color/blob/b0d364ff63957ee5253e42d270663c537631337e/src/components/Chrome.vue#L138-L142
https://github.com/xiaokaike/vue-color/blob/b0d364ff63957ee5253e42d270663c537631337e/src/mixin/color.js#L88-L90

Since support of this library seems to be discontinued, I'd rather proceed with proposal to migrate to native solution: #6096

Native color pickers seems to accept shortened HEX colors, so it will be automatically resolved: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/color#providing_a_default_color