[tests/repository] use the new connection api (part 2/2)
Some notes:
* module imports cleanup
* the unimplemented `test_transaction_interleaved` is wiped
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')