Update grid stack to latest to resolve jQuery vulnerability.

[aksswami]

What are the steps to reproduce?

Use retireJS to scan for vulnerability in node-red project. It will have this output.

jquery 3.4.1 has known vulnerabilities: severity: medium; CVE: CVE-2020-11022, summary: Regex in its jQuery.htmlPrefilter sometimes may introduce XSS; https://blog.jquery.com/2020/04/10/jquery-3-5-0-released/ severity: medium; CVE: CVE-2020-11023, summary: Regex in its jQuery.htmlPrefilter sometimes may introduce XSS; https://blog.jquery.com/2020/04/10/jquery-3-5-0-released/
/Users/xxxxxx/src/node_modules/gridstack/dist/jquery.min.js
 ↳ jquery 3.4.1

What happens?

What do you expect to happen?

We should update gridstack to the latest version which is already using JQuery 3.5.0

Please tell us about your environment:

• [x] Node-RED-Dashboard version: 2.30.0
• [x] Node-RED version: 2.0.6
• [x] node.js version: 14.x
• [x] npm version:6.7.x
• [x] Platform/OS: OSX
• [ ] Browser:

[dceejay]

This is non-trivial as this is a major version jump to gridstack and they have broken several API that we use - so the code will need to be re-implemented. However it is not obvious how this vulnerability can be exploited from code as we use it.