Check for redacted font

[cassidyjames]

We hardcode "Redacted Script Regular" and "Redacted Script Light" in the app, but we don't depend on them at all. This leads to an unexpected experience on other platforms; instead, we should depend on the package that provides the redacted font.

[codygarver]

It's not possible/sensible to "depend" on a package of assets as if they are C headers or something similar because it would only affect build time, when you build from source and then directly run the app. The packaging is what is meant to ensure runtime dependencies, which already does depend on this package.

Instead, the code should check for the existence of the fonts on the system and disable the feature if they're not found.