add file view - closed file tree trigger

Created by: 5h1rU

Sidebar with files and symbols button new styles.

Utility classes on bootstrap add !important. That's why a property on the sass file replaced the border radius.

1. refresh design on
2. refresh design off

https://user-images.githubusercontent.com/989826/118855331-47dc6580-b89b-11eb-8208-0015f41a29ec.mov

Figma Design

• stickersheet
• mockup