Fix a few lints

lib/const_data/kanji_grades.dart

@@ -1,6 +1,5 @@
 /// Jouyou kanji sorted primarily by grades and secondarily by strokes.
-const Map<int, Map<int, List<String>>>
-JOUYOU_KANJI_BY_GRADE_AND_STROKE_COUNT = {
+const Map<int, Map<int, List<String>>> jouyouKanjiByGradeAndStrokeCount = {
   1: {
     1: ['一'],
     2: ['力', '八', '入', '二', '人', '十', '七', '九'],
@@ -1861,8 +1860,8 @@ JOUYOU_KANJI_BY_GRADE_AND_STROKE_COUNT = {
   },
 };
 
-final Map<int, List<String>> JOUYOU_KANJI_BY_GRADES =
-    JOUYOU_KANJI_BY_GRADE_AND_STROKE_COUNT.entries
+final Map<int, List<String>> jouyouKanjiByGrades =
+    jouyouKanjiByGradeAndStrokeCount.entries
         .expand((entry) => entry.value.entries)
         .map((entry) => MapEntry(entry.key, entry.value))
         .fold<Map<int, List<String>>>(

lib/const_data/radicals.dart

@@ -1,4 +1,4 @@
-const Map<int, List<String>> RADICALS = {
+const Map<int, List<String>> radicals = {
   1: ['一', '｜', '丶', 'ノ', '乙', '亅'],
   2: [
     '二',