💄(frontend) refactor feedbacks screen

Enhance initial screen. Allow user returning to the meeting.
Also, add basic and non-functional rating component to mock,
what the form would be.

src/frontend/src/locales/de/rooms.json

@@ -1,7 +1,8 @@
 {
   "feedback": {
-    "body": "",
-    "heading": ""
+    "heading": "",
+    "home": "",
+    "back": ""
   },
   "join": {
     "videoinput": {
@@ -109,6 +110,14 @@
   "chat": {
     "disclaimer": ""
   },
+  "rating": {
+    "submit": "",
+    "question": "",
+    "levels": {
+      "min": "",
+      "max": ""
+    }
+  },
   "participants": {
     "subheading": "",
     "contributors": "",