util/NumberParser: rename to CNumberParser

A new NumberParser library based on std::from_chars() will be added.

src/util/CNumberParser.cxx

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: BSD-2-Clause
 // author: Max Kellermann <max.kellermann@gmail.com>
 
-#include "NumberParser.hxx"
+#include "CNumberParser.hxx"
 
 #include <algorithm>
 #include <iterator>

src/util/meson.build

@@ -3,7 +3,7 @@ util = static_library(
   'Exception.cxx',
   'UTF8.cxx',
   'MimeType.cxx',
-  'NumberParser.cxx',
+  'CNumberParser.cxx',
   'TruncateString.cxx',
   'StringStrip.cxx',
   'StringUtil.cxx',