Code review comment for lp:~stub/launchpad/bug-354035

Address Bug #354035

This branch adds an identifier for the Store being used to the SQL statement logs. At the moment, this will normally be something like 'launchpad-main-master'. launchpad is the config section in launchpad-lazr.conf being used for database configuration, 'main' is the Store realm, 'master' is the Store flavour. The format of the identifier may change in the future, but it should remain a simple string.

Care has been taken to ensure old format OOPS reports are still loaded. The Store identifier is None for these OOPS reports.

I expect this will break some of the external OOPS handling tools, so requesting a review from matsubara to help identify what this will break and what to do about it.

There were some minor drive by lint and code standard cleanups.