Reflect PK of referred table if referred columns not present

Reflect PK of referred table if referred columns not present

Fixed bug where a FOREIGN KEY that was set up to refer to the parent table
by table name only without the column names would not correctly be
reflected as far as setting up the "referred columns", since SQLite's
PRAGMA does not report on these columns if they weren't given explicitly.
For some reason this was harcoded to assume the name of the local column,
which might work for some cases but is not correct. The new approach
reflects the primary key of the referred table and uses the constraint
columns list as the referred columns list, if the remote column(s) aren't
present in the reflected pragma directly.

Fixes: #4810
Change-Id: I7789f83d68845ae197a782080af8ec64a7bf48cc