fix(resolution): read a quoted Python annotation as a receiver type (#1684) (#1770)

`def f(o: "Alpha")` is the same annotation as `def f(o: Alpha)` — a
forward reference, and what every file under `from __future__ import
annotations` writes — but the receiver-type pattern stopped at the quote,
read no type, and `o.render()` produced no edge. Admit the quoted form.

Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>

__tests__/python-quoted-annotation.test.ts

@@ -0,0 +1,55 @@
+/**
+ * A quoted (forward-reference) parameter annotation names a receiver type too
+ * (#1684): `def f(o: "Alpha")` resolves `o.render()` exactly like `def f(o:
+ * Alpha)`. Quoted annotations are ordinary Python — forward references, and
+ * everything under `from __future__ import annotations`.
+ */
+import { describe, it, expect, beforeAll, afterAll } from 'vitest';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import { CodeGraph } from '../src';
+import { initGrammars, loadAllGrammars } from '../src/extraction/grammars';
+
+let dir: string;
+let cg: CodeGraph;
+
+beforeAll(async () => {
+  await initGrammars();
+  await loadAllGrammars();
+  dir = fs.mkdtempSync(path.join(os.tmpdir(), 'cg-1684-'));
+  fs.mkdirSync(path.join(dir, 'pkg'));
+  fs.writeFileSync(path.join(dir, 'pkg', '__init__.py'), '');
+  fs.writeFileSync(
+    path.join(dir, 'pkg', 'a.py'),
+    'def render(x):\n    return x\n\nclass Alpha:\n    def render(self):\n        return "a"\n\nclass Beta:\n    def render(self):\n        return "b"\n'
+  );
+  fs.writeFileSync(
+    path.join(dir, 'pkg', 'b.py'),
+    'from __future__ import annotations\nfrom pkg.a import Alpha, Beta\n\n' +
+      'def quoted(o: "Alpha"):\n    return o.render()\n\n' +
+      "def single_quoted(o: 'Beta'):\n    return o.render()\n\n" +
+      'def unquoted(o: Alpha):\n    return o.render()\n'
+  );
+  cg = CodeGraph.initSync(dir);
+  await cg.indexAll();
+});
+
+afterAll(() => {
+  cg.destroy();
+  fs.rmSync(dir, { recursive: true, force: true });
+});
+
+const calleeOf = (fn: string): string[] =>
+  cg
+    .getCallees(cg.getNodesByName(fn).find((n) => n.kind === 'function')!.id)
+    .map(({ node }) => node.qualifiedName)
+    .sort();
+
+describe('quoted forward-reference annotations (#1684)', () => {
+  it('resolves the method on the quoted type, the same as the unquoted annotation', () => {
+    expect(calleeOf('unquoted')).toEqual(['Alpha::render']);
+    expect(calleeOf('quoted')).toEqual(['Alpha::render']);
+    expect(calleeOf('single_quoted')).toEqual(['Beta::render']);
+  });
+});