[0.2.1] add an option to pin the sidebar in search

[Sivan22]

Summary

now when you scroll the search results, the sidebar closes automaticly. it is suggested that there will be a button to pin the side bar, similar to what exists in the text book reading screen

Version

0.2.1

Motivation

some times you want to change the settings after scrolling, and it is better if the sidebar will stay open.