Add paging information to /communities/{communityId}/admins/{adminId}/payments

[mslowiak]

We need to support pagination results for the frontend pagination feature.

Things to be done:

• Define PageInfo class
• Apply that class to ListAdminPaymentsResponse as another property called pageInfo
• Update api.yaml schema
• Update and fix tests

CC: @Tobi406

[mslowiak]

A new model for a response, in that case, would include the PageInfo object @Tobi406.

Example:

{
  "payments": [
    {
      "adminId": "string",
      "paymentId": "string",
      "charge": 0,
      "dueDate": "string"
    }
  ],
  "pageInfo": {
    "currentPage": 0,
    "pageLimit": 0,
    "totalPages": 0,
    "totalElements": 0
  }
}