Add: multiple signature fields

[plocket]

Mostly showing there's no variable name associated with the 'field' itself. name="_event" has the trigger var name encoded, but in future will not.

<section id="daquestion" class="tab-pane active offset-xl-3 offset-lg-3 col-xl-6 col-lg-6 offset-md-2 col-md-8">
  <div class="dasigpage" id="dasigpage">
    <div class="dasigshowsmallblock dasigheader d-block d-sm-none" id="dasigheader" style="">
      <div class="dasiginnerheader">
        <a href="#" role="button" class="btn btn-sm btn-warning dasignav-left dasignavbutton dasigclear">Clear</a>
        <a href="#" role="button" class="btn btn-sm btn-primary dasignav-right dasignavbutton dasigsave">Continue</a>
        <div id="dasigtitle" class="dasigtitle">Signature 1</div>
      </div>
    </div>
    <div class="dasigtoppart" id="dasigtoppart">
      <div id="daerrormess" class="dasigerrormessage dasignotshowing">You must sign your name to continue.</div>
      <div class="da-page-header d-none d-sm-block">
        <h1 class="h3">Signature 1</h1>
        <div class="daclear"></div>
      </div>
    </div>
    <div id="dasigmidpart" class="dasigmidpart"></div>
    <div id="dasigcontent" style="height: 180px;">
      <canvas id="dasigcanvas" width="450px" height="180px"></canvas>
    </div>
    <div class="dasigbottompart" id="dasigbottompart">
    </div>
    <fieldset class="da-button-set d-none d-sm-block da-signature">
      <legend class="sr-only">Press one of the following buttons:</legend>
      <div class="form-actions dasigbuttons mt-3">
        <a href="#" role="button" class="btn btn-primary btn-da dasigsave">Continue</a>
        <a href="#" role="button" class="btn btn-warning btn-da dasigclear">Clear</a>
      </div>
    </fieldset>
  </div>
  <form aria-labelledby="dasigtitle" action="/interview?i=docassemble.playground12ALTestingExpand%3Aall_tests.yml" id="dasigform" method="POST"><input type="hidden" name="_save_as" value="c2lnbmF0dXJlXzE"><input type="hidden" id="da_sig_required" value="1"><input type="hidden" id="da_ajax" name="ajax" value="0"><input type="hidden" id="da_the_image" name="_the_image" value=""><input type="hidden" id="da_success" name="_success" value="0"> <input type="hidden" name="csrf_token" value="ImNkNDhhMzgyYWE1YjZlOWIyNGM2NjBlM2QwMzYwZTRhMzc2Zjg5Zjci.YNj4kw.LaGGNdoNmkvwoobb3Wdh-i5dxUU">
    <input type="hidden" name="_event" value="WyJzaWduYXR1cmVfMSJd">
    <input type="hidden" name="_question_name" value="ID first signature">
    <input type="hidden" name="_tracker" value="16">
  </form>
  <div class="d-block d-md-none"><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br></div>
  <div class="dasigpost">
    <div data-variable="c2lnbmF0dXJlXzE" id="trigger" aria-hidden="true" style="display: none;"></div>
  </div>
</section>