Create Reward Default endpoint

[sameersubudhi]

Description

Create the following endpoint.

HTTP GET /api/v3/reward/default
RPC  get.reward.default

Acceptance Criteria

• The endpoints listed above are created
• The response is matching as described below
• All the methods, variables, files are renamed appropriately
• Swagger is up-to-date
• Integration tests are up-to-date

Additional information

Request params:

Parameter	Type	Validation	Default	Comment
height	Number	[0, ∞)	(empty)	Block height

Responses:

200 OK

{
  "data": {
    "defaultReward": "0",
    "tokenID": "0000000000000000"
  },
  "meta": {}
}

400 Bad Request

{
  "error": true,
  "message": "Unknown input parameter(s): <param_name>"
}