Type loss in json expression updates

[stoch]

JSON objects can be displayed and also updated by using DDerl Queries like this one:

select ckey, cvalue:SHORTID, cvalue:CONSTATE 
from tpac where length(ckey) = 4 
and safe_string(nth(3, ckey)) = to_string('lacon')

The current 'convenience' hack to represent Strings without qotes (and escaped quotes inside) is not lossless. Imem sometimes looses the type information on the update (converts SHORTID to an integer in this case).