LibCore: Remove a bunch of unnecessary forward declarations

Now that we get LibCore forward declarations from <LibCore/Forward.h>,
we don't need to declare things manually.

Libraries/LibCore/HttpJob.h

@@ -33,8 +33,6 @@
 
 namespace Core {
 
-class TCPSocket;
-
 class HttpJob final : public NetworkJob {
     C_OBJECT(HttpJob)
 public:

Libraries/LibCore/HttpRequest.h

@@ -29,11 +29,11 @@
 #include <AK/Optional.h>
 #include <AK/String.h>
 #include <AK/URL.h>
+#include <AK/Vector.h>
+#include <LibCore/Forward.h>
 
 namespace Core {
 
-class NetworkJob;
-
 class HttpRequest {
 public:
     enum Method {

Libraries/LibCore/LocalServer.h

@@ -31,8 +31,6 @@
 
 namespace Core {
 
-class LocalSocket;
-
 class LocalServer : public Object {
     C_OBJECT(LocalServer)
 public:

Libraries/LibCore/LocalSocket.h

@@ -30,8 +30,6 @@
 
 namespace Core {
 
-class LocalServer;
-
 class LocalSocket final : public Socket {
     C_OBJECT(LocalSocket)
 public:

Libraries/LibCore/NetworkJob.h

@@ -31,8 +31,6 @@
 
 namespace Core {
 
-class NetworkResponse;
-
 class NetworkJob : public Object {
     C_OBJECT_ABSTRACT(NetworkJob)
 public:

Libraries/LibCore/Socket.h

@@ -32,8 +32,6 @@
 
 namespace Core {
 
-class Notifier;
-
 class Socket : public IODevice {
     C_OBJECT(Socket)
 public:

Libraries/LibCore/TCPServer.h

@@ -32,8 +32,6 @@
 
 namespace Core {
 
-class TCPSocket;
-
 class TCPServer : public Object {
     C_OBJECT(TCPServer)
 public:

Libraries/LibCore/TCPSocket.h

@@ -31,8 +31,6 @@
 
 namespace Core {
 
-class TCPServer;
-
 class TCPSocket final : public Socket {
     C_OBJECT(TCPSocket)
 public: