Refactor constants values (THEMES.json and CONFIGS.json)

[mateuszkornecki]

Is your feature request related to a problem? Please describe.
After creating the userRole enum I realised that the THEMES.json and CONFIGS.json files are prolly redundant we can safety refactor the way initial configs or themes are stored in the app. There is probably a better, more cleaner way to achieve the sama or better results. Moreover it will be much easier to create the TS types if the hardcoded values will be stored in a different way.
Describe the solution you'd like
I would like to see a different, simpler way of storing default values that will automatically create types from those values.
Describe alternatives you've considered
I was thinking about introducing more enums for some of the configs.

[mateuszkornecki]

THEMES>jsonis now a ts file, CONFIG left...
seemore at #165