(5R,6R,7R,9R,13R,14S)‐21‐Cyclo­propyl­meth­yl‐6,14‐endo‐ethano‐2′,3′,4′,5′,7,8‐hexa­hydro‐4′,4′,5′,5′‐tetra­methyl­furano[2′,3′6,7]normorphide hydro­chloride methanol solvate