Unique values within multiple instances of the same symbol
**Which version of the plugin are you using?**
[3.0 ] Data Populator for Sketch

**Is your feature request related to a problem? Please describe.**
As someone who uses atomic design principles, it would be awesome for Data Populator to work with this layer structure. Right now when I run Data Populator on a symbol used multiple times within a larger symbol, the returned values are the same repeated over and over.

**Describe the solution you'd like**
* Lets say I have a symbol with a {label}
* I import 4 instances of said symbol into a new symbol
* When I run data popular, the {label} should receive unique values from the data source.

**Describe alternatives you've considered**
The only other way to do this I can imagine is not having my instances within a larger symbol. 

**Additional context**
I feel like this has probably been asked, but I cannot seem to find a topic covering it. Apologies if this is a beaten horse.