Lagom+LibCore: Build LibCore, AK, and LibMain with add_subdirectory

By deferring to the CMakeLists in each of these libraries' directories,
we can get rid of a lot of curious GLOB patterns and list removals in
the Lagom CMakeLists.

Userland/Libraries/LibCore/CMakeLists.txt

@@ -1,21 +1,17 @@
 set(SOURCES
     AnonymousBuffer.cpp
     ArgsParser.cpp
-    ConfigFile.cpp
     Command.cpp
+    ConfigFile.cpp
     DateTime.cpp
     Directory.cpp
     DirIterator.cpp
     ElapsedTimer.cpp
     Event.cpp
     EventLoop.cpp
-    FileWatcher.cpp
     File.cpp
-    FilePermissionsMask.cpp
-    GetPassword.cpp
-    Group.cpp
+    FileWatcher.cpp
     IODevice.cpp
-    LocalServer.cpp
     LockFile.cpp
     MappedFile.cpp
     MimeData.cpp
@@ -28,8 +24,8 @@ set(SOURCES
     SecretString.cpp
     SessionManagement.cpp
     SOCKSProxyClient.cpp
-    Stream.cpp
     StandardPaths.cpp
+    Stream.cpp
     System.cpp
     SystemServerTakeover.cpp
     TCPServer.cpp
@@ -38,8 +34,14 @@ set(SOURCES
     UDPServer.cpp
     Version.cpp
 )
-if (NOT ANDROID)
-    list(APPEND SOURCES Account.cpp)
+if (NOT ANDROID AND NOT WIN32)
+    list(APPEND SOURCES
+        Account.cpp
+        FilePermissionsMask.cpp
+        GetPassword.cpp
+        Group.cpp
+        LocalServer.cpp
+    )
 endif()
 
 serenity_lib(LibCore core)