Add button_url[] and hypertext element to allow mods to open web pages (#13825)

Fixes #12500

src/util/colorize.h

@@ -0,0 +1,34 @@
+/*
+Part of Minetest
+Copyright (C) 2024 rubenwardy
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include <string>
+#include "config.h"
+
+#define COLOR_CODE(color) "\x1b(c@" color ")"
+
+#ifdef USE_CURL
+
+/**
+ * Colorize URL to highlight the hostname and any unsafe characters
+ *
+ * Throws an exception if the url is invalid
+ */
+std::string colorize_url(const std::string &url);
+
+#endif