RFR: 8351339: WebSocket::sendBinary assume that user supplied buffers are BIG_ENDIAN [v6]

[Volkan Yazici]

> Fixes endian handling `jdk.internal.net.http.websocket.Frame.Masker`.
> 
> ### Implementation notes
> 
> I deleted the `Frame` clone in tests, and rewired the test code depending on it to the actual `Frame`. To enable this, I relaxed the visibility of the actual `Frame`. I guess the `Frame` clone was introduced to have strict visibility in the actual `Frame`. Though this is not needed since the actual `Frame` is in an internal package. Plus, the fact that bug is in the `Frame` class hints in the direction that there should be one `Frame`.

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

 - Merge remote-tracking branch 'origin/wsEndian' into wsEndian
 - Improve JavaDoc
 - Add `TEST.properties` injecting `jdk.internal.net.http.websocket`

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24033/files
  - new: https://git.openjdk.org/jdk/pull/24033/files/7c465ebb..047465ca

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24033&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24033&range=04-05

  Stats: 38 lines in 19 files changed: 6 ins; 17 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/24033.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24033/head:pull/24033

PR: https://git.openjdk.org/jdk/pull/24033