Kernel: Split the ProcFS core file into smaller components

Author: https://github.com/supercomputer7
Commit: 3906dd3aa3
Pull-request: https://github.com/SerenityOS/serenity/pull/15771
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/bgianfo

Kernel/ProcessProcFSTraits.cpp

@@ -4,8 +4,9 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <Kernel/FileSystem/ProcFS.h>
+#include <Kernel/FileSystem/ProcFS/ProcessDirectoryInode.h>
 #include <Kernel/Process.h>
+#include <Kernel/ProcessExposed.h>
 
 namespace Kernel {