[BOOT:LIB] Add boot option size helpers

BOOT/ENVIRON/INC/bootlib.h

@@ -23,6 +23,16 @@ typedef struct {
     ULONG Flags;
 } BOOT_LIBRARY_PARAMETERS, *PBOOT_LIBRARY_PARAMETERS;
 
+ULONG
+BlGetBootOptionSize (
+    IN PBOOT_APPLICATION_ENTRY_OPTION Option
+    );
+
+ULONG
+BlGetBootOptionListSize (
+    IN PBOOT_APPLICATION_ENTRY_OPTION Options
+    );
+
 NTSTATUS
 BlInitializeLibrary (
     IN PBOOT_INPUT_PARAMETERS InputParameters,