RFR: 8350279: HttpClient: Add a new HttpResponse method to identify connections [v3]

[Volkan Yazici]

> Adds `HttpResponse::connectionLabel` method that provides an identifier for the connection.
> 
> **Implementation note:** The feature is facilitated by `HttpConnection::label`, which should not be confused with `HttpConnection::id`. This distinction is explained in the JavaDoc of both properties.

Volkan Yazici has updated the pull request incrementally with two additional commits since the last revision:

 - Add import for `java.net.http.HttpClient.Version` in `HttpResponseConnectionLabelTest`
 - Fix indentation

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/24154/files
  - new: https://git.openjdk.org/jdk/pull/24154/files/028999a7..a08c0cf1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24154&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24154&range=01-02

  Stats: 15 lines in 2 files changed: 1 ins; 0 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/24154.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24154/head:pull/24154

PR: https://git.openjdk.org/jdk/pull/24154