closes https://github.com/TryGhost/Team/issues/2222
Whilst we were checking for Stripe objects being active, we were not
checking for them existing in Stripe. This adds handling to all read
request to Stripe in the payment link flow, so that we can gracefully
handle deleted objects.
We've also included an automated test which fails without this fix.
We've also improved the query to find Stripe Prices which will result
in less request to the Stripe API to check if it is valid.
refs https://github.com/TryGhost/Team/issues/1166
This is a new module which will eventually handle all payment related
things. This allows the Offers module to focus exclusively on the Ghost
concepts, and the Payments module will handle the association between
Offer & Stripe Coupon, Tier & Stripe Product, Cadence & Stripe Price.
This decoupling allows us to not have to consider the lack of Stripe
data for an Offer, which is the case after a Stripe Disconnect. Instead
all of the population/repopulation/lazy-creating can be handled here.