Allow horizontal scrolling with Shift+Scroll in EntryView.

Allows horizontal scrolling when pressing Shift + Scroll. This is currently limited to the EntryView.

The code changes are minimal: We listen to wheelEvent and forward it to the parent or the horizontal scrollbar depending on whether Shift is pressed or not.

Implements feature: #11337

Testing strategy

Tested locally.

Type of change

• ✅ New feature (change that adds functionality)

You can already achieve this by pressing ALT and scrolling.