Handle M2 customer deleted, SP customer not deleted, new M2 customer created

[chrismshea]

PRs: #246

Steps to reproduce:

• A customer can request their account to be deleted on Magento.
• They can then create a new account using the same email address.
• When they create a new subscription they will have created it for a customer in SP that has their old ID.
• We then do the reorder, and attempt to create a cart using the old customer id.

Expected:

• When they create a new subscription, new SP customer record is created
• Old SP customer record gets marked as orphaned, email is changed to: Cur. Email + "-ORPHANED-" + unique ID
• New SP customer record gets their new email and new M2 customer ID

Algorithm

• Lookup SP Customer based on M2 customer ID
  • If found, use it
  • If not found
    • Lookup SP customer based on customer email
      • If not found, create new customer
      • If found
        • Update existing SP customer record, change email to: Cur. Email + "-ORPHANED-" + unique ID
        • Create new customer