Update references from onDark to inverse

[Jordan Jones]

Is your feature request related to a problem? Please describe.

With the new token theming work, we have decided to change the naming of dark themed tokens to ending in -inverse instead of -on-dark. This needs to be reflected in the built out list of tokens.

Describe the solution you'd like

Change the naming convention of the tokens from onDark to inverse for the dark themed tokens in their respective JSON files.

Describe alternatives you've considered

N/A

Additional context

N/A

[Jordan Jones]

This is a duplicate ticket and this work is already done.