cadctap get_table_schema should check for more than utype

[SlaterRGordon]

right now when determining the column type it only checks for the utype attribute, it should probably also check for the datatype attribute and have them stored in separate columns.

These were Adrian's comments on the issue:
It should probably be based on datatype only (and not utype) which makes more sense in most cases. But it requires a bit of work and need to figure out the actual syntax. For example: denotes what most DB call varchar(128) but the extendedType is an URI. Should the tool say just varchar(128) or uri or uri(128)? utype could also be useful info. Maybe it should display all of this in separate columns. That would be ideal.