Improve control char rendering and escape button styling (#37094)

Follow-up to #37078.

- Use Unicode Control Pictures](U+2400-U+2421) to render C0 control characters
- Make it work in diff view too
- Replace escape warning emoji with SVG
- Align escape warning button with code lines

---------

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

Author: silverwind

modules/charset/ambiguous.go

@@ -1,4 +1,3 @@
-// This file is generated by modules/charset/ambiguous/generate.go DO NOT EDIT
 // Copyright 2022 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
@@ -14,11 +13,12 @@ import (
 
 // AmbiguousTablesForLocale provides the table of ambiguous characters for this locale.
 func AmbiguousTablesForLocale(locale translation.Locale) []*AmbiguousTable {
+	ambiguousTableMap := globalVars().ambiguousTableMap
 	key := locale.Language()
 	var table *AmbiguousTable
 	var ok bool
 	for len(key) > 0 {
-		if table, ok = AmbiguousCharacters[key]; ok {
+		if table, ok = ambiguousTableMap[key]; ok {
 			break
 		}
 		idx := strings.LastIndexAny(key, "-_")
@@ -29,18 +29,18 @@ func AmbiguousTablesForLocale(locale translation.Locale) []*AmbiguousTable {
 		}
 	}
 	if table == nil && (locale.Language() == "zh-CN" || locale.Language() == "zh_CN") {
-		table = AmbiguousCharacters["zh-hans"]
+		table = ambiguousTableMap["zh-hans"]
 	}
 	if table == nil && strings.HasPrefix(locale.Language(), "zh") {
-		table = AmbiguousCharacters["zh-hant"]
+		table = ambiguousTableMap["zh-hant"]
 	}
 	if table == nil {
-		table = AmbiguousCharacters["_default"]
+		table = ambiguousTableMap["_default"]
 	}
 
 	return []*AmbiguousTable{
 		table,
-		AmbiguousCharacters["_common"],
+		ambiguousTableMap["_common"],
 	}
 }
 
@@ -52,7 +52,7 @@ func isAmbiguous(r rune, confusableTo *rune, tables ...*AmbiguousTable) bool {
 		i := sort.Search(len(table.Confusable), func(i int) bool {
 			return table.Confusable[i] >= r
 		})
-		(*confusableTo) = table.With[i]
+		*confusableTo = table.With[i]
 		return true
 	}
 	return false

modules/charset/ambiguous/generate.go

@@ -8,11 +8,13 @@ import (
 	"testing"
 	"unicode"
 
+	"code.gitea.io/gitea/modules/translation"
+
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAmbiguousCharacters(t *testing.T) {
-	for locale, ambiguous := range AmbiguousCharacters {
+	for locale, ambiguous := range globalVars().ambiguousTableMap {
 		assert.Equal(t, locale, ambiguous.Locale)
 		assert.Len(t, ambiguous.With, len(ambiguous.Confusable))
 		assert.True(t, sort.SliceIsSorted(ambiguous.Confusable, func(i, j int) bool {
@@ -28,4 +30,8 @@ func TestAmbiguousCharacters(t *testing.T) {
 			assert.True(t, found, "%c is not in %d", confusable, i)
 		}
 	}
+
+	var confusableTo rune
+	ret := isAmbiguous('𝐾', &confusableTo, AmbiguousTablesForLocale(&translation.MockLocale{})...)
+	assert.True(t, ret)
 }