fix: HttpRequestLoggerServer should not keep the connection open

[iwasakims]

What this PR changes/adds

Make HttpRequestLoggerServer return Content-length: 0 instead of Transfer-encoding: chunked.

$ curl -i -X POST --data baz localhost:4000/foo/bar
HTTP/1.1 200 OK
Date: Mon, 20 Nov 2023 08:08:10 GMT
Transfer-encoding: chunked

(curl keeps waiting for response body from server)

after:

$ curl -i -X POST --data baz localhost:4000/foo/bar
HTTP/1.1 200 OK
Date: Mon, 20 Nov 2023 09:38:23 GMT
Content-length: 0

Why it does that

Setting 0 to responseLength of HttpExchange#sendResponseHeaders means chunked transfer for sending response. Clients wait for the response body until the stream os response body is closed in the server.

Linked Issue(s)

Closes #157