NmeaAisStaticDataReportParserPartB should detect short messages and provide better exception messages

[idg10]

It appears that although in theory Type 24 part B AIS messages should always be 168 bits long, in practice some hardware produces messages that are only 160 bits long.

In these cases, attempts to read fields near the end of the message (e.g., DimensionToStarboard) detect the attempted overrun and throw an exeption, but the message is generic. It would be better if this exception message indicated that the message is shorter than the spec requires, and that the property in question is therefore unavailable.