Kernel: Split the Ext2FileSystem.{cpp,h} files into smaller components

Author: https://github.com/supercomputer7
Commit: 3cc0d60141
Pull-request: https://github.com/SerenityOS/serenity/pull/15771
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/bgianfo

Kernel/Storage/StorageManagement.cpp

@@ -20,7 +20,7 @@
 #include <Kernel/CommandLine.h>
 #include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/Devices/DeviceManagement.h>
-#include <Kernel/FileSystem/Ext2FileSystem.h>
+#include <Kernel/FileSystem/Ext2FS/FileSystem.h>
 #include <Kernel/FileSystem/VirtualFileSystem.h>
 #include <Kernel/Panic.h>
 #include <Kernel/Storage/ATA/AHCI/Controller.h>