Add lwgeom_typename to report human readable error message on unknown type

[colivier]

mac:liblwgeom ol$ grep lwerror * | grep type | grep %d
g_box.c:	lwerror("unsupported type (%d)", TYPE_GETTYPE(lwgeom->type));
g_serialized.c:		lwerror("Unknown geometry type: %d", type);
g_serialized.c:		lwerror("Unknown geometry type: %d", geom->type);
g_serialized.c:		lwerror("Unknown geometry type: %d", type);
g_serialized.c:		lwerror("Unsupported geometry type: %d", type);
lwcollection.c:				lwerror("lwcollection_construct: mixed dimension geometries: %d/%d", zm, TYPE_GETZM(geoms[i]->type));
lwcollection.c:		lwerror("lwcollection_deserialize called on NON geometrycollection: %d", type);
lwcompound.c:		lwerror("lwcompound_deserialize called on non compound: %d", type);
lwcurvepoly.c:			lwerror("Only Circular curves, Linestrings and Compound curves are supported as rings, not %s (%d)", lwgeom_typename(result->rings[i]->type), result->rings[i]->type);
lwgeodetic.c:		lwerror("unsupported input geometry type: %d", TYPE_GETTYPE(geom->type));
lwgeodetic.c:		lwerror("unsupported input geometry type: %d", TYPE_GETTYPE(geom->type));
lwmcurve.c:		lwerror("lwmcurve_deserialize called on NON multicurve: %d", type);
lwmsurface.c:		lwerror("lwmsurface_deserialize called on a non-multisurface: %d", type);
lwout_wkt.c:			lwerror("lwcompound_to_wkt_size: Unknown type recieved %d", type);
lwout_wkt.c:				lwerror("lwcurvepoly_to_wkt_size: Unknown type recieved %d", type);
lwout_wkt.c:				lwerror("lwmcurve_to_wkt_size: Unknown type recieved %d", type);
lwout_wkt.c:				lwerror("lwmsurface_to_wkt_size: Unknown type recieved %d", type);
lwout_wkt.c:			lwerror("lwgeom_to_wkt_sb: Type %d unsupported.", TYPE_GETTYPE(geom->type));
lwsegmentize.c:			lwerror("Unsupported geometry type %d found.", lwgeom_getType(geom->type));
lwsegmentize.c:			lwerror("Invalid segment type %d.", type);
lwsegmentize.c:			lwerror("Invalid segment type %d.", type);
lwsegmentize.c:	lwerror("Invalid state %d-%d", currentType, type);

[colivier]

Done as r5791