NEW: create new file viewer with MIH package

Frontend/lib/mih_components/mih_providers/mih_file_viewer_provider.dart

@@ -0,0 +1,28 @@
+import 'package:flutter/material.dart';
+
+class MihFileViewerProvider extends ChangeNotifier {
+  String filePath;
+  String fileLink;
+  int toolIndex;
+
+  MihFileViewerProvider({
+    this.filePath = '',
+    this.fileLink = '',
+    this.toolIndex = 0,
+  });
+
+  void setToolIndex(int index) {
+    toolIndex = index;
+    notifyListeners();
+  }
+
+  void setFilePath(String path) {
+    filePath = path;
+    notifyListeners();
+  }
+
+  void setFileLink(String name) {
+    fileLink = name;
+    notifyListeners();
+  }
+}