Migrated to angular 8

Created dev configuration

src/assets/default.json

@@ -0,0 +1,22 @@
+{
+    "YoutubeDLMaterial": {
+        "Host": {
+            "frontendurl": "http://localhost:4200",
+            "backendurl": "http://localhost:17442/"
+        },
+      "Encryption": {
+        "use-encryption": false,
+        "cert-file-path": "/etc/letsencrypt/live/example.com/fullchain.pem",
+        "key-file-path": "/etc/letsencrypt/live/example.com/privkey.pem"
+      },
+      "Downloader": {
+        "path-base": "http://localhost:17442/",
+        "path-audio": "audio/",
+        "path-video": "video/"
+      },
+      "Extra": {
+        "title_top": "Youtube Downloader",
+		"file_manager_enabled": true
+      }
+    }
+  }