Update block diagnostics (#28006)

Release Notes:

- "Block" diagnostics (that show up in the diagnostics view, or when
using `f8`/`shift-f8`) are rendered more clearly
- `f8`/`shift-f8` now always go to the "next" or "prev" diagnostic,
regardless of the state of the editor

![Screenshot 2025-04-09 at 16 42
09](https://github.com/user-attachments/assets/ae6d2ff6-5183-4b74-89d0-fefee1aa11e3)

---------

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Co-authored-by: Julia Ryan <juliaryan3.14@gmail.com>

Cargo.lock

@@ -4315,19 +4315,24 @@ dependencies = [
  "anyhow",
  "client",
  "collections",
+ "component",
  "ctor",
  "editor",
  "env_logger 0.11.8",
  "gpui",
+ "indoc",
  "language",
+ "linkme",
  "log",
  "lsp",
+ "markdown",
  "pretty_assertions",
  "project",
  "rand 0.8.5",
  "serde",
  "serde_json",
  "settings",
+ "text",
  "theme",
  "ui",
  "unindent",