rpcdaemon: limit default max number of output traces in trace_filter

[Sixtysixter]

Calling trace_filter API by providing toBlock >> fromBlock causes a long call execution.
For example:

{
  "request": {
    "id": 1,
    "jsonrpc": "2.0",
    "method": "trace_filter",
    "params": [
      {
        "fromBlock": 152918,
        "toBlock": 2446688
      }
    ]
  }

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": [
      {
        "action": {
        "callType": "call",
        "from": "0x52bc44d5378309ee2abf1539bf71de1b7d7be3b5",
        "gas": "0x7148",
        "input": "0x",
        "to": "0xef4f88a89dde9340a4ec680498aa1787ad608d8f",
        "value": "0xb301e9c3d8fe10"
      },
   ]
}

In order to mitigate this problem, we should limit the maximum number of traces contained in the response result to N, where N could be hard-coded or passed via CLI.
Such value N acts as a default value for the count input parameter.