WebSocket Protocol and Version support

[Industrial]

Hi.

These are the headers sent between client and server on the WebSocket: https://tools.ietf.org/html/rfc6455#section-11.3.5

This PR adds support for Protocol and Version headers.

[CLAassistant]

All committers have signed the CLA.

[Industrial]

I'm not sure why the tests failed. It has nothing to do with my code, I think. What now?

[bartlomieju]

Thanks for the PR @Industrial, LGTM, but please add assertions exercising this change to WS tests

[ry]

@Industrial We have a couple flaky of rare tests at the moment - pushing an empty commit can reset a failure.

[bartlomieju]

@Industrial I'm still interested in landing this PR, but to do that we'll need signed CLA and some small test case exercising new code.

[Industrial]

@bartlomieju Hi, I'm currently not in the position (hit some bad times) to write the test code and I will not be for several months probably. I signed the CLA.

[bartlomieju]

@bartlomieju Hi, I'm currently not in the position (hit some bad times) to write the test code and I will not be for several months probably. I signed the CLA.

@Industrial sorry to hear that. I'll add test cases, thank you for your contribution.

[bartlomieju]

Closing in favor of #8505