update elements and fix some bugs

lib/src/prism/tests/languages/csharp/keyword_feature.test

+abstract as async await base
+bool break byte case catch
+char checked
+class;
+const continue
+decimal default delegate do
+double else enum event explicit
+extern false finally fixed float
+for foreach goto if implicit in
+int
+interface;
+internal is lock
+long namespace
+new;
+null object
+operator out override params
+private protected public readonly
+ref return sbyte sealed short
+sizeof stackalloc static string
+struct switch this throw true
+try typeof uint ulong unchecked
+unsafe ushort using virtual void
+volatile while add alias ascending
+async await descending dynamic
+from get global group into
+join let orderby partial remove
+select set value var where yield
+
+----------------------------------------------------
+
+[
+        ["keyword", "abstract"], ["keyword", "as"], ["keyword", "async"], ["keyword", "await"], ["keyword", "base"],
+        ["keyword", "bool"], ["keyword", "break"], ["keyword", "byte"], ["keyword", "case"], ["keyword", "catch"],
+        ["keyword", "char"], ["keyword", "checked"],
+        ["keyword", "class"], ["punctuation", ";"],
+        ["keyword", "const"], ["keyword", "continue"],
+        ["keyword", "decimal"], ["keyword", "default"], ["keyword", "delegate"], ["keyword", "do"],
+        ["keyword", "double"], ["keyword", "else"], ["keyword", "enum"], ["keyword", "event"], ["keyword", "explicit"],
+        ["keyword", "extern"], ["keyword", "false"], ["keyword", "finally"], ["keyword", "fixed"], ["keyword", "float"],
+        ["keyword", "for"], ["keyword", "foreach"], ["keyword", "goto"], ["keyword", "if"], ["keyword", "implicit"], ["keyword", "in"],
+        ["keyword", "int"],
+        ["keyword", "interface"], ["punctuation", ";"],
+        ["keyword", "internal"], ["keyword", "is"], ["keyword", "lock"],
+        ["keyword", "long"], ["keyword", "namespace"],
+        ["keyword", "new"], ["punctuation", ";"],
+        ["keyword", "null"], ["keyword", "object"],
+        ["keyword", "operator"], ["keyword", "out"], ["keyword", "override"], ["keyword", "params"],
+        ["keyword", "private"], ["keyword", "protected"], ["keyword", "public"], ["keyword", "readonly"],
+        ["keyword", "ref"], ["keyword", "return"], ["keyword", "sbyte"], ["keyword", "sealed"], ["keyword", "short"],
+        ["keyword", "sizeof"], ["keyword", "stackalloc"], ["keyword", "static"], ["keyword", "string"],
+        ["keyword", "struct"], ["keyword", "switch"], ["keyword", "this"], ["keyword", "throw"], ["keyword", "true"],
+        ["keyword", "try"], ["keyword", "typeof"], ["keyword", "uint"], ["keyword", "ulong"], ["keyword", "unchecked"],
+        ["keyword", "unsafe"], ["keyword", "ushort"], ["keyword", "using"], ["keyword", "virtual"], ["keyword", "void"],
+        ["keyword", "volatile"], ["keyword", "while"], ["keyword", "add"], ["keyword", "alias"], ["keyword", "ascending"],
+        ["keyword", "async"], ["keyword", "await"], ["keyword", "descending"], ["keyword", "dynamic"],
+        ["keyword", "from"], ["keyword", "get"], ["keyword", "global"], ["keyword", "group"], ["keyword", "into"],
+        ["keyword", "join"], ["keyword", "let"], ["keyword", "orderby"], ["keyword", "partial"], ["keyword", "remove"],
+        ["keyword", "select"], ["keyword", "set"], ["keyword", "value"], ["keyword", "var"], ["keyword", "where"], ["keyword", "yield"]
+]
+
+----------------------------------------------------
+
+Checks for all keywords.