[api-minor] Support Named-actions in the outline (issue 15367)

Apparently this is implemented in e.g. Adobe Reader, and the specification does support it, however it cannot be commonly used in real-world PDF documents since it took over ten years for this feature to be requested.

test/pdfs/.gitignore

@@ -50,6 +50,7 @@
 !issue7439.pdf
 !issue7847_radial.pdf
 !issue14953.pdf
+!issue15367.pdf
 !issue7446.pdf
 !issue7492.pdf
 !issue7544.pdf

test/unit/api_spec.js

@@ -1535,6 +1535,7 @@ describe("api", function () {
       expect(outline.length).toEqual(6);
 
       expect(outline[4]).toEqual({
+        action: null,
         dest: "Händel -- Halle🎆lujah",
         url: null,
         unsafeUrl: undefined,
@@ -1550,6 +1551,31 @@ describe("api", function () {
       await loadingTask.destroy();
     });
 
+    it("gets outline, with named-actions (issue 15367)", async function () {
+      const loadingTask = getDocument(buildGetDocumentParams("issue15367.pdf"));
+      const pdfDoc = await loadingTask.promise;
+      const outline = await pdfDoc.getOutline();
+
+      expect(Array.isArray(outline)).toEqual(true);
+      expect(outline.length).toEqual(4);
+
+      expect(outline[1]).toEqual({
+        action: "PrevPage",
+        dest: null,
+        url: null,
+        unsafeUrl: undefined,
+        newWindow: undefined,
+        title: "Previous Page",
+        color: new Uint8ClampedArray([0, 0, 0]),
+        count: undefined,
+        bold: false,
+        italic: false,
+        items: [],
+      });
+
+      await loadingTask.destroy();
+    });
+
     it("gets outline with non-displayable chars", async function () {
       const loadingTask = getDocument(buildGetDocumentParams("issue14267.pdf"));
       const pdfDoc = await loadingTask.promise;