Problem: Code lenses currently display as virtual text on the same line
and after the relevant item. While the spec does not say how lenses
should be rendered, above the line is most typical. For longer lines,
lenses rendered as virtual text can run off the side of the screen.
Solution: Display lenses as virtual lines above the text.
Closes https://github.com/neovim/neovim/issues/33923
Co-authored-by: Yi Ming <ofseed@foxmail.com>