Fix missing prefund field when --unsafe is used

[thaarok]

When the bundler is running with --unsafe, following error prevents sending UserOps:

failed:  eth_sendUserOperation error: {"message":"invalid BigNumber value (argument=\"value\", value=undefined, code=INVALID_ARGUMENT, version=bignumber/5.7.0)","code":"INVALID_ARGUMENT"} Error: invalid BigNumber value (argument="value", value=undefined, code=INVALID_ARGUMENT, version=bignumber/5.7.0)
    at Logger.makeError (.../bundler/node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
    at Logger.throwError (.../bundler/node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
    at Logger.throwArgumentError (.../bundler/node_modules/@ethersproject/logger/src.ts/index.ts:285:21)
    at Function.BigNumber.from (.../bundler/node_modules/@ethersproject/bignumber/src.ts/bignumber.ts:289:23)
    at toBN (.../bundler/node_modules/@ethersproject/bignumber/src.ts/bignumber.ts:345:27)
    at BigNumber.lt (.../bundler/node_modules/@ethersproject/bignumber/src.ts/bignumber.ts:159:30)
    at BundleManager.createBundle (.../bundler/packages/bundler/src/modules/BundleManager.ts:422:41)
    at processTicksAndRejections (node:internal/process/task_queues:105:5)
    at async .../bundler/packages/bundler/src/modules/BundleManager.ts:89:51 {
  reason: 'invalid BigNumber value',
  code: 'INVALID_ARGUMENT',
  argument: 'value',
  value: undefined
}

This field is provided by tracing (when --unsafe is not used), but not by the dummy info struct.
This add this field into the dummy info structure.