Saturn logging fixes

[guanzo]

There's a few issues that need to be fixed for Saturn logging.

• The URL should be the URL that was requested. Currently it's an ip address
  

  caboose/pool.go

  Line 368 in ebf9e25

  URL: from,

  It should be this template with values filled in.

  caboose/pool.go

  Line 342 in ebf9e25

  var saturnReqTmpl = "https://%s/ipfs/%s?format=raw"

• Rename localTime to startTime
  

  caboose/pool.go

  Line 369 in ebf9e25

  LocalTime: start,

• Rename requestDuration to requestDurationSec
  

  caboose/pool.go

  Line 372 in ebf9e25

  RequestDuration: durationSecs,

• Log is missing a nodeId field. The value is obtained from the Saturn-Node-Id response header.

• requestId should be obtained from the Saturn-Transfer-Id response header instead of generating a UUID.
  

  caboose/pool.go

  Line 346 in ebf9e25

  requestId := uuid.NewString()

• cacheHit should be obtained from the Saturn-Cache-Status response header instead of hardcoding to false.
  Check if the response header value equals HIT.
  

  caboose/pool.go

  Line 367 in ebf9e25

  CacheHit: false,

• numBytesSent should include the size of the headers.
  

  caboose/pool.go

  Lines 370 to 371 in ebf9e25

  	// TODO: does this include header sizes?
  	NumBytesSent: received,

• clientAddress and userAgent do not need to be set in the logs as the receiving server can obtain both fields from the request.
  

  caboose/pool.go

  Line 378 in ebf9e25

  ClientAddress: "",

• If a range request was sent, the value should have the same format as the Range request header ( bytes=<start>-<end>). Otherwise an empty string is fine.
  

  caboose/pool.go

  Line 379 in ebf9e25

  Range: "",

• Log is missing an ifNetworkError field. If a request fails due to a network error (a connection was never established, a response was never received, a TLS error, etc), this value should be set with the error message. It doesn't need to be sent if null.

• Please add a nodeIpAddress field. The IP address of the saturn node you sent the request to.

• The log POST request should include this request header: Authorization: Bearer <base64_jwt>.
  The jwt will be provided to the Caboose DRI.

More info here: https://www.notion.so/pl-strflt/Saturn-Payments-Logging-8db8d7b691a9471aaf786947a6b8b0a6