[ty] IDE: only provide declarations and bindings as completions (#18456)

## Summary

Previously, all symbols where provided as possible completions. In an
example like the following, both `foo` and `f` were suggested as
completions, because `f` itself is a symbol.
```py
foo = 1

f<CURSOR>
```
Similarly, in the following example, `hidden_symbol` was suggested, even
though it is not statically visible:
```py
if 1 + 2 != 3:
    hidden_symbol = 1

hidden_<CURSOR>
```

With the change suggested here, we only use statically visible
declarations and bindings as a source for completions.


## Test Plan

- Updated snapshot tests
- New test for statically hidden definitions
- Added test for star import

crates/ty_python_semantic/src/semantic_model.rs

@@ -10,6 +10,7 @@ use crate::module_resolver::{Module, resolve_module};
 use crate::semantic_index::ast_ids::HasScopedExpressionId;
 use crate::semantic_index::semantic_index;
 use crate::semantic_index::symbol::FileScopeId;
+use crate::types::ide_support::all_declarations_and_bindings;
 use crate::types::{Type, binding_type, infer_scope_types};
 
 pub struct SemanticModel<'db> {
@@ -66,9 +67,10 @@ impl<'db> SemanticModel<'db> {
         };
         let mut symbols = vec![];
         for (file_scope, _) in index.ancestor_scopes(file_scope) {
-            for symbol in index.symbol_table(file_scope).symbols() {
-                symbols.push(symbol.name().clone());
-            }
+            symbols.extend(all_declarations_and_bindings(
+                self.db,
+                file_scope.to_scope_id(self.db, self.file),
+            ));
         }
         symbols
     }

crates/ty_python_semantic/src/types.rs

@@ -65,7 +65,7 @@ mod diagnostic;
 mod display;
 mod function;
 mod generics;
-mod ide_support;
+pub(crate) mod ide_support;
 mod infer;
 mod instance;
 mod mro;

crates/ty_python_semantic/src/types/ide_support.rs

@@ -8,6 +8,37 @@ use crate::types::{ClassBase, ClassLiteral, KnownClass, Type};
 use ruff_python_ast::name::Name;
 use rustc_hash::FxHashSet;
 
+pub(crate) fn all_declarations_and_bindings<'db>(
+    db: &'db dyn Db,
+    scope_id: ScopeId<'db>,
+) -> impl Iterator<Item = Name> + 'db {
+    let use_def_map = use_def_map(db, scope_id);
+    let symbol_table = symbol_table(db, scope_id);
+
+    use_def_map
+        .all_public_declarations()
+        .filter_map(move |(symbol_id, declarations)| {
+            if symbol_from_declarations(db, declarations)
+                .is_ok_and(|result| !result.symbol.is_unbound())
+            {
+                Some(symbol_table.symbol(symbol_id).name().clone())
+            } else {
+                None
+            }
+        })
+        .chain(
+            use_def_map
+                .all_public_bindings()
+                .filter_map(move |(symbol_id, bindings)| {
+                    if symbol_from_bindings(db, bindings).is_unbound() {
+                        None
+                    } else {
+                        Some(symbol_table.symbol(symbol_id).name().clone())
+                    }
+                }),
+        )
+}
+
 struct AllMembers {
     members: FxHashSet<Name>,
 }
@@ -118,24 +149,8 @@ impl AllMembers {
     }
 
     fn extend_with_declarations_and_bindings(&mut self, db: &dyn Db, scope_id: ScopeId) {
-        let use_def_map = use_def_map(db, scope_id);
-        let symbol_table = symbol_table(db, scope_id);
-
-        for (symbol_id, declarations) in use_def_map.all_public_declarations() {
-            if symbol_from_declarations(db, declarations)
-                .is_ok_and(|result| !result.symbol.is_unbound())
-            {
-                self.members
-                    .insert(symbol_table.symbol(symbol_id).name().clone());
-            }
-        }
-
-        for (symbol_id, bindings) in use_def_map.all_public_bindings() {
-            if !symbol_from_bindings(db, bindings).is_unbound() {
-                self.members
-                    .insert(symbol_table.symbol(symbol_id).name().clone());
-            }
-        }
+        self.members
+            .extend(all_declarations_and_bindings(db, scope_id));
     }
 
     fn extend_with_class_members<'db>(