[dataimport] add tests for SQLGenObjectStore (closes #9177565)
Stolen from the massive import store, with the irrelevant bits removed.
Remove redundant tests from test_pgstore.py.
option_group_changed('port', 'main', 'web')
option_group_changed('query-log-file', 'main', 'web')
option_group_changed('profile', 'main', 'web')
option_group_changed('max-post-length', 'main', 'web')