feat(customer): app data rest api

[hekike]

Changes

• Remove app data and observer from customer pkg
• Add list, upsert, delete customer data to app
• Moves app factory to service level
• Define new API
• Wire up new API

Examples

Get customer apps with customer app data

GET /api/v1/customers/{customer_id}/apps

Upsert customer app data with app type

PUT /api/v1/customers/{customer_id}/apps

[
  {
    "type": "stripe",
    "stripeCustomerId": "cus_xxx"
  }
]

Upsert customer app with app ID

PUT /api/v1/customers/{customer_id}/apps

[
  {
    "id": "{app_id}",
    "type": "stripe",
    "stripeCustomerId": "cus_xxx"
  }
]

Delete customer app data by app ID

DELETE /api/v1/customers/{customer_id}/apps/{app_id}