clean repo for angular update to 12

mc_frontend/package.json

@@ -19,11 +19,11 @@
   "dependencies": {
     "@angular-builders/custom-webpack": "11",
     "@angular/animations": "^12.2.17",
-    "@angular/cdk": "^11.2.13",
+    "@angular/cdk": "^12.2.13",
     "@angular/common": "^12.2.17",
     "@angular/core": "^12.2.17",
     "@angular/forms": "^12.2.17",
-    "@angular/material": "^11.2.13",
+    "@angular/material": "^12.2.13",
     "@angular/platform-browser": "^12.2.17",
     "@angular/platform-browser-dynamic": "^12.2.17",
     "@angular/router": "^12.2.17",