[dataimport] separate entities table from other metadata in SQLGenObjectStore
'entities' needs to be updated first as every other table has references
to its rows. Remove use of thread-local storage in the process.
related to #9177565.
import ConfigParser
try:
undo_actions = config.cfgfile_parser.get('MAIN', 'undo-support', False)
except ConfigParser.NoOptionError:
pass # this conf. file was probably already migrated
else:
config.global_set_option('undo-enabled', bool(undo_actions))