Feature/96 member and account details on payment page

[kirillta]

Back-end logic for #96

1. /api/payments/:memberCode removed
2. /api/payments/:memberCode/prepare renamed to /api/payments/:memberCode
3. An account operating name, a facility name, and basic pro-forma invoice details were added. For now proFormaInvoice.amount is always null that means a customer may pay any amount of tips. proFormaInvoice.serviceFee is always AED 2.9 for now.

The full method response is:

{
  "member": {
    "id": 1,
    "accountName": "Afterlife",
    "avatarUrl": "https://s3.eu-central-1.amazonaws.com/tipcat-net-avatars/accounts/4/members/1",
    "facilityName": "Afterlife Mercs",
    "firstName": "Rogue",
    "lastName": "Amendiares",
    "position": null
  },
  "clientSecret": null,
  "paymentIntentId": null,
  "proFormaInvoice": {
    "amount": null,
    "serviceFee": {
      "amount": 2.9,
      "currency": "AED"
    }
  }
}

[sergeyf-QA]

Summary:

• /api/payments/:memberCode removed
• /api/payments/:memberCode/prepare renamed to /api/payments/:memberCode
• an account operating name, a facility name, and basic pro-forma invoice details exist
• GET /api/payments/{memberCode} returns response according to the Kirill's model above

OK on DEV.