Unable to scroll when there are many folders

[Aaron-Bird]

Description

Scroll bar and search bar cannot be displayed when there are many folders.

Issue fixed

#3486 Can't scroll in sidebar

before

after

When the scroll bar is hidden

Type of changes

• 🔘 Bug fix (Change that fixed an issue)
• ⚪ Breaking change (Change that can cause existing functionality to change)
• ⚪ Improvement (Change that improves the code. Maybe performance or development improvement)
• ⚪ Feature (Change that adds new functionality)
• ⚪ Documentation change (Change that modifies documentation. Maybe typo fixes)

Checklist:

• 🔘 My code follows the project code style
• ⚪ I have written test for my code and it has been tested
• ⚪ All existing tests have been passed
• 🔘 I have attached a screenshot/video to visualize my change if possible

[Flexo013]

I like this a lot! Thanks a lot for the PR (and the explanatory gifs)!

[ZeroX-DG]

LGTM 🎉 the only problem that I found is the lable on hover will start to show at the wrong location once you scroll down. If you can fix it in this PR then it would be great but otherwise we can create separate PR to fix it later.