Devtools Network page displays unreadable string instead of json

### Use case

when debuging using network page i have difficulties reading the request json, compared to response page it's clear and readable

### Proposal

make the page of request in devtools network page displays json format

Start by locating the DevTools Network page's request-body rendering and compare it with the response-body rendering shown in the report. Done means request JSON is displayed in a readable, formatted form rather than as an unreadable string.

Written by the indexing model from the issue text.