Add a function that checks if a target language is in the supported languages list. Add some calls to this function where appropriate in UefiLib.c Cc: Michael D Kinney <michael.d.kinney@intel.com> Cc: Liming Gao <liming.gao@intel.com> Signed-off-by: Tom Zhao <tzhao@solarflare.com> Reviewed-by: Liming Gao <liming.gao@intel.com>