Improve package template

[James-Mart]

• Adds prompts to template generation
  • psibase version
  • description
• Adds name validation
  • name doesn't contain numbers (it messes up the wit naming requirements)
  • name <= 12 characters (makes it much more likely the account name will successfully roundtrip)
• Adds default tasks.json to generated app. If new app is opened as a new workspace in vscode, you will see UI buttons for "Build UI" and "Build package"
• Separates query service into separate service
• Adds query for historical event emission
• Add service unit test (in separate file)
• Adds a default readme for the generated app
• Add missing dependency on Sites package (caused boot to fail if package was used at boot)
• Generates app into a directory named "MyApp" (upper camel case) instead of "my-app" to match existing app naming conventions
• Uses split wit file convention (world.wit, impl.wit) to match existing wit conventions and make imports simpler

[cool-ant]

This PR seems to replace/improve on the package-templates folder and should (I believe) remove that folder.

[swatanabe]

This PR seems to replace/improve on the package-templates folder and should (I believe) remove that folder.

I think it does, and github is getting confused for some reason. I see renames when I examine it in git.