LibFileSystem+Everywhere: Return ByteString current_working_directory()

That is, return it *from* current_working_directory(), but I didn't have
room. :^)

Meta/Lagom/Tools/ConfigureComponents/main.cpp

@@ -234,7 +234,7 @@ int main()
     auto current_working_directory = FileSystem::current_working_directory();
     if (current_working_directory.is_error())
         return 1;
-    auto lexical_cwd = LexicalPath(current_working_directory.release_value().to_byte_string());
+    auto lexical_cwd = LexicalPath(current_working_directory.release_value());
     auto& parts = lexical_cwd.parts_view();
     if (parts.size() < 2 || parts[parts.size() - 2] != "Build") {
         warnln("\e[31mError:\e[0m This program needs to be executed from inside 'Build/*'.");

Userland/Applications/FileManager/main.cpp

@@ -142,7 +142,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }
 
     if (auto error_or_cwd = FileSystem::current_working_directory(); initial_location.is_empty() && !error_or_cwd.is_error())
-        initial_location = error_or_cwd.release_value().to_byte_string();
+        initial_location = error_or_cwd.release_value();
 
     if (initial_location.is_empty())
         initial_location = Core::StandardPaths::home_directory();

Userland/Libraries/LibFileSystem/FileSystem.cpp

@@ -23,10 +23,9 @@
 
 namespace FileSystem {
 
-ErrorOr<String> current_working_directory()
+ErrorOr<ByteString> current_working_directory()
 {
-    auto cwd = TRY(Core::System::getcwd());
-    return TRY(String::from_byte_string({ cwd }));
+    return Core::System::getcwd();
 }
 
 ErrorOr<String> absolute_path(StringView path)

Userland/Libraries/LibFileSystem/FileSystem.h

@@ -18,7 +18,7 @@ namespace FileSystem {
 #define DEFAULT_PATH "/usr/local/sbin:/usr/local/bin:/usr/bin:/bin"
 #define DEFAULT_PATH_SV "/usr/local/sbin:/usr/local/bin:/usr/bin:/bin"sv
 
-ErrorOr<String> current_working_directory();
+ErrorOr<ByteString> current_working_directory();
 ErrorOr<String> absolute_path(StringView path);
 ErrorOr<String> real_path(StringView path);