Incorrect Chinese layout about tabulate

[markkurossi]

Thanks @snxq for the report and fix. I pushed a fix that uses the golang.org/x/text/width package to decide if a rune is an EastAsianWide character and computing the output width based on that info.

[snxq]

@markkurossi I modify some changes to solve it. Length of a Chinese character rune is 1, but print length is 2.

tabulate.go

func New(style Style) *Tabulate {
	tab := &Tabulate{
		Padding: 2,
		Borders: borders[style],
		Measure: func(column string) int {
			var l int
			for _, c := range column {
				if unicode.Is(unicode.Han, c) {
					l += 2
				} else {
					l++
				}
			}
			return l
		},
	}
	switch style {
	case Colon, Simple, SimpleUnicode, SimpleUnicodeBold:
		tab.Padding = 0
	case CSV:
		tab.Padding = 0
		tab.TrimColumns = true
		tab.Escape = escapeCSV
	case JSON:
		tab.Padding = 0
		tab.TrimColumns = true
		tab.Output = outputJSON
	}
	return tab
}