feat: LSP document symbol (#5532)

# Description

## Problem

Resolves #5533

## Summary

With this you can see where you are at any time, and jump to any symbol
in the document.



https://github.com/user-attachments/assets/74ebdb36-cd51-4afc-a33e-775156c1317b




## Additional Context

None

## Documentation

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist

- [x] I have tested the changes locally.
- [ ] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

compiler/noirc_frontend/src/ast/expression.rs

@@ -800,12 +800,8 @@ impl FunctionDefinition {
             return_visibility: Visibility::Private,
         }
     }
-}
-
-impl Display for FunctionDefinition {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        writeln!(f, "{:?}", self.attributes)?;
 
+    pub fn signature(&self) -> String {
         let parameters = vecmap(&self.parameters, |Param { visibility, pattern, typ, span: _ }| {
             if *visibility == Visibility::Public {
                 format!("{pattern}: {visibility} {typ}")
@@ -827,15 +823,14 @@ impl Display for FunctionDefinition {
             format!(" -> {}", self.return_type)
         };
 
-        write!(
-            f,
-            "fn {}({}){}{} {}",
-            self.name,
-            parameters.join(", "),
-            return_type,
-            where_clause_str,
-            self.body
-        )
+        format!("fn {}({}){}{}", self.name, parameters.join(", "), return_type, where_clause_str)
+    }
+}
+
+impl Display for FunctionDefinition {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        writeln!(f, "{:?}", self.attributes)?;
+        write!(f, "fn {} {}", self.signature(), self.body)
     }
 }
 

tooling/lsp/src/lib.rs

@@ -21,7 +21,10 @@ use async_lsp::{
 use fm::{codespan_files as files, FileManager};
 use fxhash::FxHashSet;
 use lsp_types::{
-    request::{HoverRequest, InlayHintRequest, PrepareRenameRequest, References, Rename},
+    request::{
+        DocumentSymbolRequest, HoverRequest, InlayHintRequest, PrepareRenameRequest, References,
+        Rename,
+    },
     CodeLens,
 };
 use nargo::{
@@ -45,10 +48,10 @@ use notifications::{
     on_did_open_text_document, on_did_save_text_document, on_exit, on_initialized,
 };
 use requests::{
-    on_code_lens_request, on_formatting, on_goto_declaration_request, on_goto_definition_request,
-    on_goto_type_definition_request, on_hover_request, on_initialize, on_inlay_hint_request,
-    on_prepare_rename_request, on_profile_run_request, on_references_request, on_rename_request,
-    on_shutdown, on_test_run_request, on_tests_request,
+    on_code_lens_request, on_document_symbol_request, on_formatting, on_goto_declaration_request,
+    on_goto_definition_request, on_goto_type_definition_request, on_hover_request, on_initialize,
+    on_inlay_hint_request, on_prepare_rename_request, on_profile_run_request,
+    on_references_request, on_rename_request, on_shutdown, on_test_run_request, on_tests_request,
 };
 use serde_json::Value as JsonValue;
 use thiserror::Error;
@@ -126,6 +129,7 @@ impl NargoLspService {
             .request::<request::GotoDefinition, _>(on_goto_definition_request)
             .request::<request::GotoDeclaration, _>(on_goto_declaration_request)
             .request::<request::GotoTypeDefinition, _>(on_goto_type_definition_request)
+            .request::<DocumentSymbolRequest, _>(on_document_symbol_request)
             .request::<References, _>(on_references_request)
             .request::<PrepareRenameRequest, _>(on_prepare_rename_request)
             .request::<Rename, _>(on_rename_request)