Common: Add HttpRequest to simplify HTTP requests

Too much boilerplate that is duplicated if we use curl directly.
Let's add a simple wrapper class that hides the implementation details
and just allows to simply make HTTP requests and get responses.

Source/Core/Common/CMakeLists.txt

@@ -11,6 +11,7 @@ set(SRCS
   FileUtil.cpp
   GekkoDisassembler.cpp
   Hash.cpp
+  HttpRequest.cpp
   IniFile.cpp
   JitRegister.cpp
   MathUtil.cpp