RemoveDir Task should error or prompt for confirmation when provided Directories argument is empty

### Steps to reproduce
```

```
If at runtime $(My_Local_DirPath) is empty

RemoveDir will actually execute and print this on console
Removing Directory ``` "\" ``` and will delete the entire root.

Suggestion:
1) Prompt user if they really want to delete in this particular scenario
2) Or introduce a new parameter for RemoveDir task
NoPrompt
or
Force