[Playground] Have a "Show only my code" toggle in TypeGraph View

[allenjzhang]

Clear and concise description of the problem

Currently it will show every library loaded which most of time user may not care about. Having a "Show only my code" will hide those standard libraries and only show the one from user TypeSpec..

Playground

Checklist

• Follow our Code of Conduct
• Check that this issue is about the Azure libraries for typespec. For feature request in the typespec language or core libraries file it in the TypeSpec repo
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.