Description

Use the "noun-first" form for adding NuGet packages. It was introduced in .NET SDK 9 for the CLI.
dotnet package add vs. dotnet add package

This is the form that the dotnet CLI is referencing in the official documentation.
dotnet package add command

Also use the --project flag followed by the path to the project file as suggested by the documentation. But only for apps that are not file-based.
For file-based apps keep the --file flag. (Which doesn't seem to have any official documentation...)

Updated the Aspire.Cli.Tests to expect the "noun-first" form.

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire.dev issue:
      • New issue
  • No