Improve diff file headers (#36215)

- reduce file name font size from 15px to 14px
- fix labels and buttons being cut off when their size is constrained
- change labels from monospace to sans-serif font
- move diff stats to right and change them from sum of changes to +/-
- change filemode to label and change text to match other labels

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/tree_entry_mode.go

@@ -4,7 +4,6 @@
 package git
 
 import (
-	"fmt"
 	"strconv"
 )
 
@@ -55,21 +54,38 @@ func (e EntryMode) IsExecutable() bool {
 	return e == EntryModeExec
 }
 
-func ParseEntryMode(mode string) (EntryMode, error) {
+func ParseEntryMode(mode string) EntryMode {
 	switch mode {
 	case "000000":
-		return EntryModeNoEntry, nil
+		return EntryModeNoEntry
 	case "100644":
-		return EntryModeBlob, nil
+		return EntryModeBlob
 	case "100755":
-		return EntryModeExec, nil
+		return EntryModeExec
 	case "120000":
-		return EntryModeSymlink, nil
+		return EntryModeSymlink
 	case "160000":
-		return EntryModeCommit, nil
-	case "040000", "040755": // git uses 040000 for tree object, but some users may get 040755 for unknown reasons
-		return EntryModeTree, nil
+		return EntryModeCommit
+	case "040000":
+		return EntryModeTree
 	default:
-		return 0, fmt.Errorf("unparsable entry mode: %s", mode)
+		// git uses 040000 for tree object, but some users may get 040755 from non-standard git implementations
+		m, _ := strconv.ParseInt(mode, 8, 32)
+		modeInt := EntryMode(m)
+		switch modeInt & 0o770000 {
+		case 0o040000:
+			return EntryModeTree
+		case 0o160000:
+			return EntryModeCommit
+		case 0o120000:
+			return EntryModeSymlink
+		case 0o100000:
+			if modeInt&0o777 == 0o755 {
+				return EntryModeExec
+			}
+			return EntryModeBlob
+		default:
+			return EntryModeNoEntry
+		}
 	}
 }