I would like to be able to get the default measurement units

[joaoTray]

Is your feature request related to a problem? Please describe.
The getWeight functions returns proper values for the weight, however, there is no explanation of what type of unit is. We can pass the one that we want to see, but we cannot use the values used by the user. I believe that should have a way to either:

• Get the type of Unit that was used when saving the data in Apple Health;
• Get the default settings in Apple Health for measurement Units

Describe the solution you'd like
The best would be to add to the getWeight (and maybe getHeight) functions the value that is being returned from the system together with the unit stored.

Describe alternatives you've considered
The only option that I can see is to add a select in my app to allow the user to select in my app. Which would be unnecessary if the library would return it.

Additional context
Trying to follow the request information here, but of course, I would like to say a big thank you for all the work on this library! :)