Think about the logic of environment variables

[giemic8]

Is your feature request related to a problem? Please describe.
As user I want to have a possibility to create variables where the value depends on environment.
Use well-known similar tools as a guide.

Describe the solution you'd like

You should think about how the variables are stored.
There should be an idea for how this should look in ui/ux.
There should be an idea of how this interacts with the global variables.
Add tickets for frontend and backend in #185