Support rich content in markup annotation

- use the xfa parser but in the xhtml namespace.

test/pdfs/.gitignore

@@ -479,3 +479,4 @@
 !pr12564.pdf
 !pr12828.pdf
 !secHandler.pdf
+!rc_annotation.pdf

test/pdfs/issue13915.pdf.link

@@ -0,0 +1 @@
+https://github.com/mozilla/pdf.js/files/7024938/2102.12353.pdf

test/test_manifest.json

@@ -137,6 +137,24 @@
        "type": "eq",
        "annotations": true
     },
+    {  "id": "issue2966",
+       "file": "pdfs/rc_annotation.pdf",
+       "md5": "7b978a8c2871b8902656adb67f7bd117",
+       "rounds": 1,
+       "lastPage": 1,
+       "type": "eq",
+       "annotations": true
+    },
+    {  "id": "issue13915",
+      "file": "pdfs/issue13915.pdf",
+      "md5": "fef3108733bbf80ea8551feedb427b1c",
+      "rounds": 1,
+      "firstPage": 51,
+      "lastPage": 51,
+      "link": true,
+      "type": "eq",
+      "annotations": true
+   },
     {  "id": "bug946506",
        "file": "pdfs/bug946506.pdf",
        "md5": "c28911b5c31bdc337c2ce404c5971cfc",

test/unit/xfa_parser_spec.js

@@ -46,7 +46,7 @@ describe("XFAParser", function () {
           forbidden
         </dynamicRender>
       </acrobat7>
-      <autoSave>enabled</autoSave>      
+      <autoSave>enabled</autoSave>
       <submitUrl>
                  http://d.e.f
       </submitUrl>
@@ -414,7 +414,7 @@ describe("XFAParser", function () {
         [
           " The first line of this paragraph is indented a half-inch.\n",
           " Successive lines are not indented.\n",
-          " This is the last line of the paragraph.\n \n",
+          " This is the last line of the paragraph.\n ",
         ].join("")
       );
     });