"Hide file tree browser" tooltip should only show on hover
# Context
When users open the file tree browser, the `Hide file tree browser` tooltip is shown every single time. This is both annoying, and an odd user experience, as users expect tooltips to appear on hover. Having a tooltip appear on open of the file tree also adds unnecessary visual clutter to GitLab's information-dense UI.
{width=900 height=597}
# Design proposal
The `Hide file tree browser` tooltip should only appear **on hover** of the file tree browser button when the file tree browser is open:
{width=900 height=597}
issue