Closes#39028
Fixed empty lines appearing when collapsing files with diagnostic
messages in the diagnostics panel.
Added a flag to track when processing a `FoldedBuffer` and skip
`Near/Below` blocks (diagnostic messages) that immediately follow it.
This prevents diagnostics from rendering as empty lines when their file
is collapsed.
Before:
<img width="1489" height="429" alt="before"
src="https://github.com/user-attachments/assets/5e233290-1f6e-403c-a6b3-a65107586d01"
/>
After:
<img width="981" height="270" alt="after"
src="https://github.com/user-attachments/assets/a877b651-6b7f-4441-805c-38ea41e73a18"
/>
Release Notes:
- Fixed empty lines when collapsing files with diagnostics in the
diagnostics panel
Vinicius da Motta
f9a2724a8b