Tariff moved to Point in Time DB architecture.

This adds oplog tables for TARIC tables and reconstructs current state
with the help of DB views. It enables us to rollback to any point time
backwards.

This enables TARIC validations that we have currently in place. The
validation framework was rewritten to have reasonable record error
messages.

TARIC importer got upgrade in relation with enabled validations. It also
uses less memory due to reduced usage of Nokogiri (uses hashes for
record parsing now).
Remove empty concern.
Missing migration, bad merge
Move data migration to later date

Since changes to oplog structure were made in parallel this migration
tries to run its query on view tables and fails. We have to apply to
oplog table.
Fix Measure conformance validations

Fixes ME6, ME13, ME14 to support meursing additional codes
Remove db/schema.rb

Sequel does not yet support view creation in schema file.