Detect ordered result sets in TestScript properly

issue 1350: TestCrashAPI: PageStore.freeListPagesPerList

Fix window functions in queries with HAVING

this looks like some kind of race condition where we are attempting to compact a PageStore which has not been properly opened yet.
Various places in Database are touching the pageStore without being synchronized, so fix those and lets see if that helps

Error handling improvements

Forbid incorrect nesting of aggregates and window functions

Parse GENERATED * AS IDENTITY correctly

Fix subtraction of timestamps

close file/release lock on failures

Assorted minor changes in window processing code