Add a simple DSL in dummy_tx.json

[mohanson]

Allowed write {{ data path/to/script }} and {{ hash path/to/script }} in tx.json.

Example: https://github.com/mohanson/ckb-standalone-debugger/blob/syscall_spawn/ckb-debugger/examples/spawn.json

{
  "mock_info": {
    "inputs": [
      {
        "input": {
          "since": "0x0",
          "previous_output": {
            "tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000002",
            "index": "0x0"
          }
        },
        "output": {
          "capacity": "0x10000000",
          "lock": {
            "code_hash": "{{ hash spawn_caller_strcat }}",
            "hash_type": "data1",
            "args": "0x"
          },
          "type": null
        },
        "data": "0x",
        "header": null
      }
    ],
    "cell_deps": [
      {
        "cell_dep": {
          "out_point": {
            "tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000001",
            "index": "0x0"
          },
          "dep_type": "code"
        },
        "output": {
          "capacity": "0x10000000",
          "lock": {
            "code_hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
            "hash_type": "data1",
            "args": "0x"
          },
          "type": null
        },
        "data": "{{ data spawn_caller_strcat }}",
        "header": null
      },
      {
        "cell_dep": {
          "out_point": {
            "tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000001",
            "index": "0x1"
          },
          "dep_type": "code"
        },
        "output": {
          "capacity": "0x10000000",
          "lock": {
            "code_hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
            "hash_type": "data1",
            "args": "0x"
          },
          "type": null
        },
        "data": "{{ data spawn_callee_strcat }}",
        "header": null
      }
    ],
    "header_deps": []
  },
  "tx": {
    "version": "0x0",
    "cell_deps": [
      {
        "out_point": {
          "tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000001",
          "index": "0x0"
        },
        "dep_type": "code"
      },
      {
        "out_point": {
          "tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000001",
          "index": "0x1"
        },
        "dep_type": "code"
      }
    ],
    "header_deps": [],
    "inputs": [
      {
        "since": "0x0",
        "previous_output": {
          "tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000002",
          "index": "0x0"
        }
      }
    ],
    "outputs": [
      {
        "capacity": "0x0",
        "lock": {
          "code_hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
          "hash_type": "data1",
          "args": "0x"
        },
        "type": {
          "code_hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
          "hash_type": "data1",
          "args": "0x"
        }
      }
    ],
    "outputs_data": [
      "0x"
    ],
    "witnesses": [
      "0x"
    ]
  }
}