Add purchasable items

[KallynGowdy]

Each item can be configured to grant a role to the user who purchased it.

• [ ] Users can choose whether to associate purchase with their account or get granted an accessKey
  • If a user chooses to use an accessKey, then an access key is generated and granted the role from the purchasable item when the purchase completes.
  • In such a case, the accessKey should be included in the redirect for the user.
• [ ] accessKeys are inactive by default. Upon first use, it should ask the user if they want to activate their key.
• [ ] Product records have the following data:
  • [ ] A unique name
  • [ ] A Stripe Purchase Link
  • [ ] A redirect URL
  • [ ] A role that is granted
  • [ ] markers
  • This might change in the future, but the gist is simple: there is a data structure that lets people store purchasable items in their records and that item contains a way to redirect the user to a product page, a role that is granted, and a URL that the user is redirected to.
• [ ] os.requestPurchase(recordName, productName)
  • Requests that the current user purchase the product from the given record.
  • This should end up finding the purchasable item and redirect the user to the purchase link with additional information about the exact product that is being purchased.
  • Before redirecting to Stripe, CasualOS should record an invoice for the event. This invoice will be used to track the payment status of the purchase.
  • After purchase, CasualOS should ask the user if they want to use their account or get an access key ("I want this for myself" vs "I want a gift card").
  • Finally, CasualOS can grant the role to the user or accessKey depending on what the user chose.
  • CasualOS should react to Stripe webhooks to respond to events regarding payment status.
• [ ] os.recordPurchasableItem(recordName, item)

[KallynGowdy]

Moved to CasualWare project.