[Feature Request] sidebar with env variabless

Hello,

It will be nice if we can show hide a sidebar with the computed env variables. Somethimes it is hard to know what are you actually sending.

The issue names no files, tests, or entry points; start by locating the request editor's sidebar UI and the code that computes environment variables. Done means users can show or hide a sidebar that displays the computed variables used by the request, making the values being sent easier to inspect.

Written by the indexing model from the issue text.