Try to convert dss.Properties.Value() return to numbers

### Feature Request

The return of `dss.Properties.Value()` is always a string. That leaves it to the higher-level application to attempt to convert the strings to a float or int. A secondary effect is that `dss.utils.class_to_dataframe()` also returns numeric data as strings.

Can OpenDSSDirect perform the conversion automatically so that users don't have to do it? I'm sure that you don't want to break the existing API. And perhaps you would prefer to push this to users.