Feat: statusline showing a straight line

[epheien]

Requested feature

Can we implement a statusline like the one in the picture? Such a statusline makes it easy to distinguish the boundaries of different windows

I am currently using incline+lightline to implement it, but it would be better if lualine.nvim could implement it.

Motivation

When using multiple windows, the inactive statusline cannot be used as a clear window boundary, especially when some windows have cursorline enabled.