Add filename as ExtendedProp to GameSet's tables

This will allow for an easy way to identify which tables came from the
standard gameset (std.set) and which came from RES files in the DBF
format. This should, eventually, help resolve issues #11, #12 and #37.

SkaaEditorUI/Project.cs

@@ -312,6 +312,7 @@ public static Tuple<Sprite, DataSet> LoadResIdxMultiBmp(string filepath, ColorPa
         {
             Sprite spr = new Sprite();
             DataTable dt = new DataTable();
+            dt.ExtendedProperties.Add("FileName", filepath);
             dt.Columns.Add(new DataColumn() { DataType = typeof(string), ColumnName = "FrameName" });
             dt.Columns.Add(new DataColumn() { DataType = typeof(uint), ColumnName = "FrameOffset" });
 
@@ -359,6 +360,7 @@ public static Tuple<Sprite, DataSet> LoadResDbf(string filepath, ColorPalette pa
                     throw new Exception("Failed to read DBF file.");
 
                 file.DataTable.TableName = Path.GetFileNameWithoutExtension(filepath);
+                file.DataTable.ExtendedProperties.Add("FileName", filepath);
                 ds.Tables.Add(file.DataTable);
             }
 

SkaaGameDataLib/GameSetFile.cs

@@ -62,6 +62,7 @@ public static bool OpenGameSet(this DataSet ds, Stream str)
                 DbfFile file = new DbfFile();
                 if (file.ReadStream(str) != true) return false;
                 file.DataTable.TableName = Path.GetFileNameWithoutExtension(kv.Key);// + ".dbf");
+                file.DataTable.ExtendedProperties.Add("FileName", (str as FileStream)?.Name);
                 ds.Tables.Add(file.DataTable);
             }
             return true;