fix(diagnostic): allow virtual_{lines,text} cursor exclusivity #33517

Problem:
virtual_text diagnostics are great when skimming a file, and
virtual_lines are great when "zooming in" on a particular problem.
Having both enabled results in duplicate diagnostics on-screen.

Solution:
This PR expands the behavior of `current_line` for virtual_text and
virtual_lines by making `virtual_text.current_line = false` distinct
from `nil`.  If you set:

    vim.diagnostic.config({
      virtual_text = { current_line = false },
      virtual_lines = { current_line = true },
    })

With this configuration, virtual_text will be used to display
diagnostics until the cursor reaches the same line, at which point they
will be hidden and virtual_lines will take its place.

0 files changed, 0 insertions, 0 deletions