Added API endpoints classes for all CFCore web API endpoints.

A few have not been implemented.

CFCoreAPI/Endpoints/Files/Requests/ModFilesRequest.cs

@@ -0,0 +1,19 @@
+using System.Text.Json.Serialization;
+
+namespace CFCoreAPI.Endpoints.Files.Requests
+{
+    public class ModFilesRequest
+    {
+        [JsonConstructor]
+        public ModFilesRequest(
+            List<int> modIds
+        )
+        {
+            this.ModIds = modIds;
+        }
+
+        public IReadOnlyList<int> ModIds { get; }
+    }
+
+
+}