Ensure that getDocument handles Node.js Buffers more gracefully (issue 13075)

While the JSDocs have never advertised `getDocument` as supporting Node.js `Buffer`s, that apparently doesn't stop users from passing such data structures to `getDocument`.
In theory the existing `instanceof Uint8Array` check ought to have caught Node.js `Buffer`s, however for reasons that I don't even pretend to understand that check actually passes. Hence this patch which, *only* in Node.js environments, will special-case `Buffer`s to hopefully provide a slightly better out-of-the-box behaviour in Node.js environments[1].

---
[1] Although I'm not sure that we necessarily want to advertise this in the JSDocs, given the specialized use-case.

Author: Snuffleupagus

src/display/api.js

@@ -243,9 +243,22 @@ function getDocument(src) {
     } else if (key === "worker") {
       worker = source[key];
       continue;
-    } else if (key === "data" && !(source[key] instanceof Uint8Array)) {
+    } else if (key === "data") {
       // Converting string or array-like data to Uint8Array.
       const pdfBytes = source[key];
+      if (
+        typeof PDFJSDev !== "undefined" &&
+        PDFJSDev.test("GENERIC") &&
+        isNodeJS &&
+        pdfBytes instanceof Buffer // eslint-disable-line no-undef
+      ) {
+        params[key] = new Uint8Array(pdfBytes);
+        continue;
+      }
+      if (pdfBytes instanceof Uint8Array) {
+        params[key] = pdfBytes;
+        continue;
+      }
       if (typeof pdfBytes === "string") {
         params[key] = stringToBytes(pdfBytes);
       } else if (