Use character display width for table padding

Using len(...) for table cell padding produced wrong results for unicode
chracters leading to misaligned tables. Implementation changed to take
the actual terminal display width into consideration.

internal/ui/format.go

@@ -8,6 +8,8 @@ import (
 	"math/bits"
 	"strconv"
 	"time"
+
+	"golang.org/x/text/width"
 )
 
 func FormatBytes(c uint64) string {
@@ -105,3 +107,24 @@ func ToJSONString(status interface{}) string {
 	}
 	return buf.String()
 }
+
+// TerminalDisplayWidth returns the number of terminal cells needed to display s
+func TerminalDisplayWidth(s string) int {
+	width := 0
+	for _, r := range s {
+		width += terminalDisplayRuneWidth(r)
+	}
+
+	return width
+}
+
+func terminalDisplayRuneWidth(r rune) int {
+	switch width.LookupRune(r).Kind() {
+	case width.EastAsianWide, width.EastAsianFullwidth:
+		return 2
+	case width.EastAsianNarrow, width.EastAsianHalfwidth, width.EastAsianAmbiguous, width.Neutral:
+		return 1
+	default:
+		return 0
+	}
+}