Give maximum file size in `/status` endpoint

[CKH4]

Status return could look like:

{
  available: true,
  maxFileSize: 131072000 // 125mb = 125 * 1024 * 1024
}

[rfornea]

I'm going to go ahead and implement this. I'm just going to call it "numChunksLimit" since that's what the broker .env variable is called, and the broker bases acceptance/rejection on numChunks. The client can interpret the number.