We now return an error when blinded and non blinded attempts are
combined. This was theoretically possible to register a legacy
attempt in combination with a blinded payment. This would have
been prevented by other checks in the code because legacy payments
are not split into shards.
This is only used for testing because we have now a unique
contraint on the session key and need to swap it in tests for
the sql backend.
pick f17baec94 paymentsdb: fix linter
This commit moves most of the code into its own package. It is
the smallest code move possible without moving import cycles and
keeping the changes to the code base as small as possible during
refactor.
ziggie