[improve] Add more information for the /api/v1/bookie/list_disk_file API

**FEATURE REQUEST**

Currently:

```shell
curl http://localhost:8000/api/v1/bookie/list_disk_file/
{
"index files" : "",
"journal files" : "xx.txn\t1213.txn\t",
"entrylog files" : "66.log\t68.log\t"
}
```

At the moment, we only get the file name, and I hope we can get more information through this interface; for example, the time of creation, the size of the file, like this:

```json
{
"entrylog files" : [
{
"66.log":{
"size":1024,
"creationTime":"1970-01-01T00:00:00Z"
}
},
{
"67.log":{
"size":1024,
"creationTime":"1970-01-01T00:00:00Z"
}
}
]
}
```
This information already exists.

But that affects the return structure, and it's a break change.

If we can't modify this interface directly, maybe we can consider adding a new API?