Remove errors after adding stricter checks

After seeting the Angular compiler options "strictTemplates" and "fullTemplateTypeCheck" to true, some new compiler errors showed up. These are corrected in this commit.

Change-Id: Ieb432865756d91fc8bcb0b7d2e724f58ec54b382
Signed-off-by: elinuxhenrik <henrik.b.andersson@est.tech>
Issue-ID: NONRTRIC-460
diff --git a/webapp-frontend/tsconfig.json b/webapp-frontend/tsconfig.json
index 5a33131..5931c27 100644
--- a/webapp-frontend/tsconfig.json
+++ b/webapp-frontend/tsconfig.json
@@ -20,5 +20,9 @@
       "es2018",
       "dom"
     ]
-  }
+  },
+    "angularCompilerOptions": {
+      "strictTemplates": true,
+      "fullTemplateTypeCheck": true
+    }
 }