Attach (recommended) or Link to PDF file here:
http://mariovalle.name/SciViz/1-s2.0-S0097849310001846-main.pdf

Configuration:
- Web browser and its version: Using pdf.js from Node.js through npm package `pdfjs-dist`
- Operating system and its version: Windows 10 64bits
- PDF.js version: 2.6.347
- Is a browser extension: No

Steps to reproduce the problem:
1. Load the file in acrobat
2. In document properties look at the Author field: it is `Samuel Silva; Beatriz Sousa Santos; Joaquim Madeira`
3. Look at  Additional metadata > advanced > dc:creator. It is marked as `seq container` and contains the 3 authors.
4. Using the code below gives: `"Author": "Samuel Silva"` that is, only the first one. And `"dc:creator": "Samuel SilvaBeatriz Sousa SantosJoaquim Madeira"`, that is the three authors squashed together without separators.

What is the expected behavior? (add screenshot)
In both fields the three authors as a single string with some sort of separator between them. Note that other pdf files that contains multiple authors already have them as a single string with names separated by commas.

The code used:
```
var pdfjsLib = require("pdfjs-dist/es5/build/pdf.js");
var pdfPath = "http://mariovalle.name/SciViz/1-s2.0-S0097849310001846-main.pdf";
var loadingTask = pdfjsLib.getDocument(pdfPath);
loadingTask.promise
  .then(function (doc) {
    var lastPromise;
    lastPromise = doc.getMetadata().then(function (data) {
      console.log(JSON.stringify(data.info, null, 2));
      if (data.metadata) {
        console.log(JSON.stringify(data.metadata.getAll(), null, 2));
      }
    });
  });
```
"</x:xmpmeta>" +
      '<?xpacket end="w"?>';
    const metadata = new Metadata(data);
    expect(isEmptyObj(metadata.getAll())).toEqual(true);
  });
  it('should gracefully handle "junk" before the actual metadata (issue 10395)', function () {
    const data =
      'ï»¿<?xpacket begin="ï»¿" id="W5M0MpCehiHzreSzNTczkc9d"?>' +
      '<x:xmpmeta x:xmptk="TallComponents PDFObjects 1.0" ' +
      'xmlns:x="adobe:ns:meta/">' +
      '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">' +
      '<rdf:Description rdf:about="" ' +
      'xmlns:pdf="http://ns.adobe.com/pdf/1.3/">' +
      "<pdf:Producer>PDFKit.NET 4.0.102.0</pdf:Producer>" +
      "<pdf:Keywords></pdf:Keywords>" +
      "<pdf:PDFVersion>1.7</pdf:PDFVersion></rdf:Description>" +
      '<rdf:Description rdf:about="" ' +
      'xmlns:xap="http://ns.adobe.com/xap/1.0/">' +
      "<xap:CreateDate>2018-12-27T13:50:36-08:00</xap:CreateDate>" +
      "<xap:ModifyDate>2018-12-27T13:50:38-08:00</xap:ModifyDate>" +
      "<xap:CreatorTool></xap:CreatorTool>" +
      "<xap:MetadataDate>2018-12-27T13:50:38-08:00</xap:MetadataDate>" +
      '</rdf:Description><rdf:Description rdf:about="" ' +
      'xmlns:dc="http://purl.org/dc/elements/1.1/">' +
      "<dc:creator><rdf:Seq><rdf:li></rdf:li></rdf:Seq></dc:creator>" +
      "<dc:subject><rdf:Bag /></dc:subject>" +
      '<dc:description><rdf:Alt><rdf:li xml:lang="x-default">' +
      "</rdf:li></rdf:Alt></dc:description>" +
      '<dc:title><rdf:Alt><rdf:li xml:lang="x-default"></rdf:li>' +
      "</rdf:Alt></dc:title><dc:format>application/pdf</dc:format>" +