Implements proper save path (#386)

* initial save path implementation

* fix savedatatype offset, remove incomplete createsavedata implimentation

* address nits

* fix crash if npdm is not found

* made saveinfo readonly, other stuff

* remove context param from saveinfo contructor

* fix style

* remove whitespace

Ryujinx.HLE/FileSystem/SaveSpaceId.cs

@@ -0,0 +1,10 @@
+namespace Ryujinx.HLE.FileSystem
+{
+    enum SaveSpaceId : byte
+    {
+        NandSystem,
+        NandUser,
+        SdCard,
+        TemporaryStorage
+    }
+}