The LibCore sockets implementation becomes WebSocketImplSerenity.
This will allow us to create a custom WebSocketImpl subclass for Qt
to use in Ladybird.
Similar reasoning to making Core::Stream::read() return Bytes, except
that every user of read_line() creates a StringView from the result, so
let's just return one right away.
A mistake I've repeatedly made is along these lines:
```c++
auto nread = TRY(source_file->read(buffer));
TRY(destination_file->write(buffer));
```
It's a little clunky to have to create a Bytes or StringView from the
buffer's data pointer and the nread, and easy to forget and just use
the buffer. So, this patch changes the read() function to return a
Bytes of the data that were just read.
The other read_foo() methods will be modified in the same way in
subsequent commits.
Fixes#13687
As LibTLS now supports the Core::Stream APIs, we can get rid of the
split paths for TCP/TLS and significantly simplify the code as well.
Provided to you free of charge by the Core::Stream-ification team :^)
