Shared config for functions and commands and taskpane

[demyte]

The crux of this change is in the manifest.xml and the main.ts

In the manifest, I have configured it so that it follows Officejs Shared Runtime Configuration

In main.ts, I have imported the commands and the functions files so the are in the main bundle and loaded into the same instance

This also includes:

• Added in a sample function and command to show and test
• Added and configured the vite-plugin-office-addin manifest plugin
• Added in the missing icons from the stnadard addin generator so the taskbar icons have one

TODO:

• Lazy load in the functions and commands so that they are JIT loaded.
• More documentation in the readme