[web/request] Restore attribute setting for search_state This was dropped in 1f84295bfe95 when `search_state` attribute was turned into a property, but without a setter. So adding a setter here restoring previous behaviour, as some tests and cubes use it. Related to #4875761.

for table, column in [
        ('transactions', 'tx_time'),
        ('tx_entity_actions', 'tx_uuid'),
        ('tx_relation_actions', 'tx_uuid')]:
    repo.system_source.create_index(session, table, column)

commit()