Fonts api with Themes integrated

Fixes:
https://github.com/adobe/brackets/issues/8425
https://github.com/adobe/brackets/issues/8381

References:
https://github.com/adobe/brackets/pull/8305

What was I thinking!?  Sorry man, I will patch that up and submit a PR.  Thanks for merging this.  Its a real nightmare to keep themes changes and fonts synced!