fix set/getSocketOption inheritance

[bertmelis]

Description of Change

• changed int WiFiClient::fd() const to virtual int WiFiClient::fd() const
• created int WiFiClientSecure::fd() const
• removed setSocketOption, getSocketOption from WiFiClientSecure to deduplicate the code.

setSocketOption, getSocketOption, getOption, and setOption in WiFiClient operate on fd(). With this fix they all operate on the correct socket.

setNoDelay and getNoDelay now also works for WiFiClientSecure.

Tests scenarios

tested using WiFiclientSecure and WiFiClient on esp32devkit v1, connected and setNoDelay.
Tested using the MQTT client as referenced to in the issue #7244

Related links

Closes #7244

[CLAassistant]

All committers have signed the CLA.

[SuGlider]

@bertmelis - Closed by mistake or is there a reason for it?

[bertmelis]

By mistake. I deleted the forked repo but I forgot I had this PR open.

[SuGlider]

By mistake. I deleted the forked repo but I forgot I had this PR open.

OK, it is not possible to merge it or to rebase it.
If possible, please, restore the branch, or maybe open a new PR.

[bertmelis]

Oh. I'll recreate it exactly the same. I deleted the repo from GitHub when doing some spring cleaning. There's no way to restore.

[bertmelis]

I recreated -not restored- the repo in the exact state as it was. I don't know if it is possible to merge in this state. IF not, I'll close this PR and create a new one.

[bertmelis]

@SuGlider Let me know if it doesn't work. I'll make a new PR.

[VojtechBartoska]

@bertmelis seems okay, you just need to update the base branch.

[bertmelis]

Well, apparently it doesn't work. I synced the branch but the update doesn't show up here. I deleted the repo by mistake and recreated it. But in this process the PR and the new fork aren't linked anymore.

[bertmelis]

Closing in favour of #7480

[VojtechBartoska]

Thanks for new PR @bertmelis!