MdeModulePkg/UdfDxe: Update GetInfo() for FS VolumeLabel info request

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1175

This commit will update the UdfGetInfo() function with the support of
EFI_FILE_SYSTEM_VOLUME_LABEL data information request.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Acked-by: Star Zeng <star.zeng@intel.com>

MdeModulePkg/Universal/Disk/UdfDxe/Udf.h

@@ -900,6 +900,33 @@ SetFileInfo (
   OUT     VOID           *Buffer
   );
 
+/**
+  Get volume label of an UDF volume.
+
+  @attention This is boundary function that may receive untrusted input.
+  @attention The input is from FileSystem.
+
+  The File Set Descriptor is external input, so this routine will do basic
+  validation for File Set Descriptor and report status.
+
+  @param[in]   Volume   Volume information pointer.
+  @param[in]   CharMax  The maximum number of Unicode char in String,
+                        including terminating null char.
+  @param[out]  String   String buffer pointer to store the volume label.
+
+  @retval EFI_SUCCESS           Volume label is returned.
+  @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
+  @retval EFI_BUFFER_TOO_SMALL  The string buffer String cannot hold the
+                                volume label.
+
+**/
+EFI_STATUS
+GetVolumeLabel (
+  IN   UDF_VOLUME_INFO  *Volume,
+  IN   UINTN            CharMax,
+  OUT  CHAR16           *String
+  );
+
 /**
   Get volume and free space size information of an UDF volume.