IDE could help to scaffold/update package.json and install the packages for unrecognized import

[RodgeFu]

Clear and concise description of the problem

We can provide a command or quickfix to help user install the missing imported packages (npm install ... with latest version) so that user can get intellisense and other authoring features for them when editing TypeSpec easily. More detail can be found in the customer feedback below:
#5521

Checklist

• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.