RFR: 8351339: WebSocket::sendBinary assume that user supplied buffers are BIG_ENDIAN [v7]

[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:

 - Add more tests
 - Guard vectorization better
 - Restore the old garbage-free state

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24033/files
  - new: https://git.openjdk.org/jdk/pull/24033/files/047465ca..41b40436

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24033&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24033&range=05-06

  Stats: 128 lines in 2 files changed: 85 ins; 38 del; 5 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