[WIP] tls: add server.sessionTimeout getter and setter.

[mkrawczuk]

This change enables dynamical change of tls.Server's session timeout. It is a follow-up to #33974.

I would like to ask for help and suggestions on writing appropriate tests for these methods. At first I wanted to count new and resumed sessions from the event callbacks, but it turned out they are not called when the client is using the session ticket feature.

[bnoordhuis]

I'd be okay with a test that tests types/ranges and verifies that setting the value is reflected by the getter.

Testing whether the session actually expires would be nice but I can see how it'd be complicated and not very reliable / timing sensitive.

[bnoordhuis]

I recognize the same style issue exists in SetSessionTimeout() but...

Suggested change

	long sessionTimeout = SSL_CTX_get_timeout(sc->ctx_.get());
	args.GetReturnValue().Set(static_cast<uint32_t>(sessionTimeout));
	long session_timeout = SSL_CTX_get_timeout(sc->ctx_.get());
	args.GetReturnValue().Set(static_cast<uint32_t>(session_timeout));

(and I'm going to guess the first line needs a // NOLINT(runtime/int) to shut up cpplint)

[bnoordhuis]

Suggested change

	// Copyright Joyent, Inc. and other Node contributors.
	//
	// Permission is hereby granted, free of charge, to any person obtaining a
	// copy of this software and associated documentation files (the
	// "Software"), to deal in the Software without restriction, including
	// without limitation the rights to use, copy, modify, merge, publish,
	// distribute, sublicense, and/or sell copies of the Software, and to permit
	// persons to whom the Software is furnished to do so, subject to the
	// following conditions:
	//
	// The above copyright notice and this permission notice shall be included
	// in all copies or substantial portions of the Software.
	//
	// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
	// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
	// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
	// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
	// USE OR OTHER DEALINGS IN THE SOFTWARE.

(not necessary in new test files)