[Feature]: allow use of environment variables in various json config files

[pcause]

Feature description

I would like to be able to use any environment variable in any config file .

Example: In a a web widget I might want to have:

"url": "$MY_HOME_PAGE"

becuase I use different home pages on my work and home systems but want to share the config file.

Implementation Suggestion

No response

Anything else?

No response