Added File Data Model

- Stores the components of a full file path
- Larger components (FullName, Path) can both be retrieved and set
- Stores all of the initial values for comparison, displaying before and after using a single list property, and reverting changes

DataModels/FileModel.cs

@@ -0,0 +1,39 @@
+namespace BulkFileRenamer.DataModels
+{
+    public class FileModel
+    {
+        public string OldName { get; }
+        public string OldFullName { get; }
+        public string OldExtension { get; }
+        public string OldDirectory { get; }
+        public string OldPath { get; }
+
+        public string Name { get; set; }
+        public string Extension { get; set; }
+        public string Directory { get; set; }
+
+        public string FullName
+        {
+            get => Extension != "" ? $"{Name}.{Extension}" : Name;
+            set
+            {
+                Name = value.LastIndexOf('.') >= 0 ? value.Substring(0, value.LastIndexOf('.')) : value;
+                Extension = value.LastIndexOf('.') >= 0 ? value.Substring(value.LastIndexOf('.') + 1, value.Length - value.LastIndexOf('.') - 1) : "";
+            }
+        }
+
+        public string Path
+        {
+            get => $"{Directory}{FullName}";
+            set
+            {
+                FullName = value.Substring(value.LastIndexOf('\\') + 1);
+                Directory = value.Substring(0, value.LastIndexOf('\\') + 1);
+            }
+        }
+
+        public FileModel(string path) =>
+            (OldPath, OldExtension, OldFullName, OldDirectory, OldName) =
+                (Path = path, Extension, FullName, Directory, Name);
+    }
+}