Refactor associations on MeasureComponent.
Refactor associations on MeasureComponent.

leftees/trade-tariff-backend,alphagov/trade-tariff-backend,leftees/trade-tariff-backend,bitzesty/trade-tariff-backend,bitzesty/trade-tariff-backend,alphagov/trade-tariff-backend,alphagov/trade-tariff-backend,leftees/trade-tariff-backend,bitzesty/trade-tariff-backend