Everywhere: Use LibFileSystem where trivial

Author: https://github.com/cammo1123
Commit: 1d24f394c6
Pull-request: https://github.com/SerenityOS/serenity/pull/17789
Reviewed-by: https://github.com/AtkinsSJ
Reviewed-by: https://github.com/caoimhebyrne
Reviewed-by: https://github.com/kleinesfilmroellchen ✅
Reviewed-by: https://github.com/linusg
Reviewed-by: https://github.com/pascalpuffke
Reviewed-by: https://github.com/timschumi ✅

Userland/DevTools/SQLStudio/MainWidget.cpp

@@ -6,10 +6,10 @@
  */
 
 #include <DevTools/SQLStudio/SQLStudioGML.h>
-#include <LibCore/DeprecatedFile.h>
 #include <LibCore/DirIterator.h>
 #include <LibCore/StandardPaths.h>
 #include <LibDesktop/Launcher.h>
+#include <LibFileSystem/FileSystem.h>
 #include <LibGUI/Action.h>
 #include <LibGUI/Application.h>
 #include <LibGUI/BoxLayout.h>
@@ -45,7 +45,7 @@ static Vector<DeprecatedString> lookup_database_names()
     static constexpr auto database_extension = ".db"sv;
 
     auto database_path = DeprecatedString::formatted("{}/sql", Core::StandardPaths::data_directory());
-    if (!Core::DeprecatedFile::exists(database_path))
+    if (!FileSystem::exists(database_path))
         return {};
 
     Core::DirIterator iterator(move(database_path), Core::DirIterator::SkipParentAndBaseDir);