Kernel/ProcFS: Split code into more separate files

Instead of using one file for the entire "backend" of the ProcFS data
and metadata, we could split that file into two files that represent
2 logical chunks of the ProcFS exposed objects:
1. Global and inter-process information. This includes all fixed data in
the root folder of the ProcFS, networking information and the bus
folder.
2. Per-process information. This includes all dynamic data about a
process that resides in the /proc/PID/ folder.

This change makes it more easier to read the code and to change it,
hence we do it although there's no technical benefit from it now :)

Kernel/CMakeLists.txt

@@ -58,6 +58,7 @@ set(KERNEL_SOURCES
     Devices/HID/PS2KeyboardDevice.cpp
     Devices/HID/PS2MouseDevice.cpp
     Devices/HID/VMWareMouseDevice.cpp
+    GlobalProcessExposed.cpp
     Graphics/Console/GenericFramebufferConsole.cpp
     Graphics/Console/ContiguousFramebufferConsole.cpp
     Graphics/Console/TextModeConsole.cpp
@@ -149,6 +150,7 @@ set(KERNEL_SOURCES
     PerformanceEventBuffer.cpp
     Process.cpp
     ProcessExposed.cpp
+    ProcessSpecificExposed.cpp
     ProcessGroup.cpp
     RTC.cpp
     Random.cpp