fix: upgrade vis-util from 4.0.0 to 4.3.4

Snyk has created this PR to upgrade vis-util from 4.0.0 to 4.3.4.

See this package in npm:
https://www.npmjs.com/package/vis-util

See this project in Snyk:
https://app.snyk.io/org/hypery2k/project/bbee2042-01b7-4d3a-b364-efc60271adb8?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -63,7 +63,7 @@
   "vis-data": "^6.6.1",
   "vis-network": "^7.6.4",
   "vis-timeline": "^7.3.6",
-  "vis-util": "^4.0.0"
+  "vis-util": "^4.3.4"
  },
  "peerDependencies": {
   "@angular/common": ">=5.0.0 || >=6.0.0 || >=7.0.0 || >=8.0.0 || >=9.0.0 || >=10.0.0 || >=11.0.0 || >=12.0.0",
@@ -148,7 +148,7 @@
   "typescript": "^3.9.2",
   "uuid": "^7.0.3",
   "vis-data": "^6.6.1",
-  "vis-util": "^4.0.0",
+  "vis-util": "^4.3.4",
   "webpack": "^4.41.3",
   "webpack-cli": "^3.3.10",
   "webpack-dev-server": "^3.11.0",