[WebSocket] Ensure TCP_NODELAY is always set

[Faless]

Almost all WebSocket implementations (including all major browsers) disable Nagle's algorithm to favor low latency over packet overhead.

This was also the case in Godot 3.x, while in Godot 4.0 this was only being done for clients and wasn't even always working due to a bug.

This commit fixes the aforementioned bug, and forces TCP_NODELAY when accepting a stream as a server.

Fixes #86234

[Faless]

Unlike what mentioned in #86234 (comment) , I decided always set the no delay option.

That was the original intent, and is in line with most implementations:

https://bugzilla.mozilla.org/show_bug.cgi?id=542401

https://issues.chromium.org/issues/41152920

https://bugs.webkit.org/show_bug.cgi?id=102079

It's worth noting that languages like go, defaults to disable the Nagle's algorithm even if most OSes would otherwise have different default (see here).

We should evaluate if we want to do something similar in Godot's socket implementation (in its own proposal/PR).

[akien-mga]

So IIUC this fixes the pre-existing docs for WebSocketPeer? As they mention "no delay" is the default.

                <method name="set_no_delay">
                        <return type="void" />
                        <param index="0" name="enabled" type="bool" />
                        <description>
                                Disable Nagle's algorithm on the underling TCP socket (default). See [method StreamPeerTCP.set_no_delay] for more information.
                                [b]Note:[/b] Not available in the Web export.
                        </description>
                </method>

BTW I notice a typo in "underling" (should be "underlying"), worth fixing in this PR while at it.

[Faless]

So IIUC this fixes the pre-existing docs for WebSocketPeer? As they mention "no delay" is the default.

Indeed, I didn't notice it was even in the documentation.

BTW I notice a typo in "underling" (should be "underlying"), worth fixing in this PR while at it.

I've added the fix for the typo.

[akien-mga]

Thanks!