Enhance processing of POSTGRES DDL

[michaelfliegner]

trafficstars

bitemp.sql.txt

ihp should integrate POSTGRES DDL needed for range types and GIST indices. Pasting my DDL from a running web app into ihp schema code editor will produce the errors I deem worth to be fixed. More on Bitemporal Persistence here

[mpscholten]

Thanks for reporting, will look into this soon 👍

[michaelfliegner]

@mpscholten I'll split that up into smaller tasks. #1761 is the first one.