feat: prioritize --columns by exact/wildcard/empty

exact: --columns sheet1!col1:number
wildcard --columns sheet1!col*:number  --columns sheet*:col1:number
empty: --columns col1:number

1. column is exact, sheet is exact
2. column is exact, sheet is wildcard
3. column is exact, sheet is empty
4. column is wildcard, sheet is exact
5. column is wildcard, sheet is wildcard
6. column is wildcard, sheet is empty

column.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"path/filepath"
 	"strings"
 )
 
@@ -15,6 +16,7 @@ type column struct {
 }
 
 func newColumn(s string, typ colType, format string) column {
+	s = strings.ToLower(s)
 	c := column{Sheet: "", Name: s, Type: typ, InputFormat: format}
 	if pos := strings.Index(s, "!"); pos != -1 {
 		c.Sheet = s[:pos]
@@ -28,21 +30,64 @@ func (cc columns) findByName(sheet, name string) int {
 		return -1
 	}
 
-	for i := range cc {
-		if strings.EqualFold(cc[i].Sheet, sheet) && strings.EqualFold(cc[i].Name, name) {
+	sheet = strings.ToLower(sheet)
+	name = strings.ToLower(name)
+
+	// name:exact, sheet:exact
+	for i, c := range cc {
+		if strings.EqualFold(c.Name, name) && strings.EqualFold(c.Sheet, sheet) {
+			return i
+		}
+	}
+
+	// name:exact, sheet:wildcard
+	for i, c := range cc {
+		if strings.EqualFold(c.Name, name) && wildcardMatch(c.Sheet, sheet) {
 			return i
 		}
 	}
 
-	for i := range cc {
-		if strings.EqualFold(cc[i].Sheet, "") && strings.EqualFold(cc[i].Name, name) {
+	// name:exact, sheet:empty
+	for i, c := range cc {
+		if strings.EqualFold(c.Name, name) && strings.EqualFold(c.Sheet, "") {
+			return i
+		}
+	}
+
+	// name:wildcard, sheet:exact
+	for i, c := range cc {
+		if wildcardMatch(c.Name, name) && strings.EqualFold(c.Sheet, sheet) {
+			return i
+		}
+	}
+
+	// name:wildcard, sheet:wildcard
+	for i, c := range cc {
+		if wildcardMatch(c.Name, name) && wildcardMatch(c.Sheet, sheet) {
+			return i
+		}
+	}
+
+	// name:wildcard, sheet:empty
+	for i, c := range cc {
+		if wildcardMatch(c.Name, name) && strings.EqualFold(c.Sheet, "") {
 			return i
 		}
 	}
 
 	return -1
 }
 
+func wildcardMatch(pattern, name string) bool {
+	if pattern == "*" {
+		return true
+	}
+	if matched, _ := filepath.Match(pattern, name); matched {
+		return true
+	}
+	return false
+}
+
 type colType string
 
 const (