Support multilang, update code

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd/FS.h

@@ -75,6 +75,9 @@ namespace fs {
 	/** @brief Returns datadir path */
 	const std::string & GetDataDir();
 
+	/** @brief Returns datadir path in UTF-8 encoding */
+	const std::string GetUTF8DataDir();
+
 	/**
 	 * @brief Set datadir either from cmdline option or using autodetection
 	 * @param cmdline_param  Value of cmdline parameter --datadir=<something>