[SG-40293] Extract bootstrap style import @import 'bootstrap/scss/reboot.scss'

Created by: gitstart-sourcegraph

Description

This PR is about extracting reboot.scss from, bootstrap to group styles

Problem statement

We depend on Bootstrap styles in our global styles a lot. But we don't plan to move forward with Bootstrap because we're working on our design system called Wildcard. To ease the transition to our styles and gain more control over visual changes, we want to move Bootstrap styles that we need into our codebase and eventually drop Bootstrap dependency.

Implementation details

1. Remove bootstrap import https://github.com/import 'bootstrap/scss/reboot.scss
2. Copy style rules used in codebase from bootstrap stylesheet

Success criteria

1. All highlighted imports have been removed
2. All CSS rules currently used from the imports are now available in style sheets

#Refs

1. Sourcegraph issue.
2. Gitstart Tickect

Test plan

• reboot.scss rules are migrated from bootstrap to global styles and redundant rules are removed
• No UI diff relating to these changes exist

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.