Update bodsdata to handle BODS 0.4 data

[kd-ods]

Having a glance through bodsdata.py, one function that will need to be updated is:

https://github.com/openownership/bodsdata/blob/0fcbc93a89218c1b7803399c902ccedc7049f8f1/bodsdata.py#

There may be others.

(I thought that the code might pass flatterer the BODS json schema(s) but I can't see that it does.)