Store wallet's data to file

URL: ```http:://127.0.0.1:11211/json_rpc```
### Request: 
```json
{
  "id": 0,
  "jsonrpc": "2.0",
  "method": "store",
  "params": {
  }
}
```
### Request description: 
```

```
### Response: 
```json
{
  "id": 0,
  "jsonrpc": "2.0",
  "result": {
    "wallet_file_size": 232243
  }
}
```
### Response description: 
```
    "wallet_file_size": Resulting file size in bytes

```
