Userland: Convert TLS::TLSv12 to a Core::Stream::Socket

This commit converts TLS::TLSv12 to a Core::Stream object, and in the
process allows TLS to now wrap other Core::Stream::Socket objects.
As a large part of LibHTTP and LibGemini depend on LibTLS's interface,
this also converts those to support Core::Stream, which leads to a
simplification of LibHTTP (as there's no need to care about the
underlying socket type anymore).
Note that RequestServer now controls the TLS socket options, which is a
better place anyway, as RS is the first receiver of the user-requested
options (though this is currently not particularly useful).

Userland/Libraries/LibHTTP/HttpRequest.cpp

@@ -6,8 +6,8 @@
 
 #include <AK/Base64.h>
 #include <AK/StringBuilder.h>
-#include <LibHTTP/HttpJob.h>
 #include <LibHTTP/HttpRequest.h>
+#include <LibHTTP/Job.h>
 
 namespace HTTP {