[ENG-5046] Preprints selectors part 2 (#2102)

## Purpose The previous PR got merged before it was completely through QA, so this contains the other test selectors that were requested. ## Summary of Changes 1. Add data-test-selectors for withdrawal justification

Author: brianjgeiger

app/preprints/-components/preprint-tombstone/template.hbs

@@ -1,8 +1,8 @@
 <div local-class='withdrawn-container'>
  {{#if @preprint.withdrawalJustification}}
- <div>
+ <div data-test-withdrawal-justification>
  <h4>{{t 'preprints.detail.reason_for_withdrawal'}}</h4>
- <p>
+ <p data-test-justification>
  {{@preprint.withdrawalJustification}}
  </p>
  </div>