Add hover effect for left sidebar

[JammingBen]

Related Issue

• Fixes Inconsistent hover effect (left sidebar) #7540

Screenshots:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[diocas]

This PR is causing a strange visual effect. When I click in the menu, the background of the entry changes immediately. But then the effect that was there before still happens, so you see 2 blue boxes merging.

In the picture you can see what happens when switching from (the previously selected) "Personal" to "Deleted files"

[kulmann]

This PR is causing a strange visual effect. When I click in the menu, the background of the entry changes immediately. But then the effect that was there before still happens, so you see 2 blue boxes merging.

In the picture you can see what happens when switching from (the previously selected) "Personal" to "Deleted files"

True... thank you! Fixed in #7575