fix (oc-docs): Multiple UI refinements in the playground

[vasharma05-bruno]

Description

This PR contains a UI refinements and improvements.

Items changed

1. Empty Response headers
2. Empty Response tests
3. Change in Overview tab display for no data in request pane
4. Spacing fixes, and title change in the request page
5. Fixed the styling for Body formatter dropdown on right of Tabs in request pane
6. Remove the title and description for tab panels in the request panel
7. Fix the coloring and spacing in Environments page
8. Fix the alignment of value being displayed in the Environment's Secret table in compact view
9. Improve the pre-request view for the response pane

Screenshots

Sidebar

Overview top spacing

No response

No response based tests

Request Page headings

No request overview page

Changed icon for send

Environments in playground

Params tab