fix: src/jcdcdev.Umbraco.ExtendedMarkdownEditor.Client/package.json & src/jcdcdev.Umbraco.ExtendedMarkdownEditor.Client/package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-UMBRACOCMSBACKOFFICE-8656563

Author: snyk-bot