Pattern modifiers are not consistent

## Description
Modifiers on the json files within patternlab are separated by `~` (button~primary.json). But the definition in the patternlab-to-gemini.json config has to be done with `-` (due to the ids within the markup).
This is not consistent.

### Expected behavior
I want to use `atoms-button~primary` as a key in the patterns section of the patternlab-to-gemini config file.