feat(n-input): customizable countTextColorDisabled

[OrbisK]

This function solves the problem (这个功能解决的问题)

so far you can not customize the color of the count, when disabled (like text or icon)

Expected API (期望的 API)

const override: GlobalThemeOverrides = {
    Input: {
        countTextColorDisabled: 'rgb(255,0,0)'
    }
}