AK: Remove the ctype adapters and use the actual ctype functions instead

This finally takes care of the kind-of excessive boilerplate code that were the
ctype adapters. On the other hand, I had to link `LibC/ctype.cpp` to the Kernel
(for `AK/JsonParser.cpp` and `AK/Format.cpp`). The previous commit actually makes
sense now: the `string.h` includes in `ctype.{h,cpp}` would require to link more LibC
stuff to the Kernel when it only needs the `_ctype_` array of `ctype.cpp`, and there
wasn't any string stuff used in ctype.
Instead of all this I could have put static derivatives of `is_any_of()` in the
concerned AK files, however that would have meant more boilerplate and workarounds;
so I went for the Kernel approach.

AK/GenericLexer.cpp

@@ -188,7 +188,7 @@ StringView GenericLexer::consume_until(const char* stop)
  */
 StringView GenericLexer::consume_quoted_string(char escape_char)
 {
-    if (!is_quote(peek()))
+    if (!next_is(is_quote))
         return {};
 
     char quote_char = consume();
@@ -264,75 +264,4 @@ void GenericLexer::ignore_until(const char* stop)
     ignore(__builtin_strlen(stop));
 }
 
-// CType adapters
-bool is_alpha(char c)
-{
-    return is_lowercase(c) || is_uppercase(c);
-}
-
-bool is_alphanum(char c)
-{
-    return is_alpha(c) || is_digit(c);
-}
-
-bool is_control(char c)
-{
-    return (c >= 0 && c <= 31) || c == 127;
-}
-
-bool is_digit(char c)
-{
-    return c >= '0' && c <= '9';
-}
-
-bool is_graphic(char c)
-{
-    return c > ' ' && c <= '~';
-}
-
-bool is_hex_digit(char c)
-{
-    return is_digit(c)
-        || (c >= 'A' && c <= 'F')
-        || (c >= 'a' && c <= 'f');
-}
-
-bool is_lowercase(char c)
-{
-    return c >= 'a' && c <= 'z';
-}
-
-bool is_path_separator(char c)
-{
-    return c == '/' || c == '\\';
-}
-
-bool is_printable(char c)
-{
-    return c >= ' ' && c <= '~';
-}
-
-bool is_punctuation(char c)
-{
-    return (c >= '!' && c <= '/')
-        || (c >= ':' && c <= '@')
-        || (c >= '[' && c <= '`')
-        || (c >= '{' && c <= '~');
-}
-
-bool is_quote(char c)
-{
-    return c == '\'' || c == '"';
-}
-
-bool is_uppercase(char c)
-{
-    return c >= 'A' && c <= 'Z';
-}
-
-bool is_whitespace(char c)
-{
-    return (c >= '\t' && c <= '\r') || c == ' ';
-}
-
 }