New command: func azure functionapp create

Needs discussion: A simplified command for creating function apps. Creates storage and app insights as well. Calls az behind the scenes.

```
func azure functionapp create $functionAppName --location $regionName
```

Automatically creates storage and app insights.

Optional params:

* `--os [windows|linux]` - defaults to linux unless not supported for runtime (inspect local functions folder for runtime/language)
* ` --sku [consumption|premium]` - defaults to consumption
* `--storage-account-name $storageAccountName` - if missing, automatically create
* `--create-app-insights [true|false]` - defaults to true

Also support a wizard to prompt for missing parameters.

Start from the proposed `func azure functionapp create` command and inspect how the local functions folder can identify the runtime and language. Define the command's Azure resource creation flow, optional parameters, defaults, and wizard behavior, then verify that it creates the function app, storage, and Application Insights as specified.

Written by the indexing model from the issue text.