Invitation displayActionConfirmationForm displays unlabelled form elements

The two inputs that are unlabelled are those with the names `memo` and `messageID`.

WCAG warnings in the test class [org.xwiki.invitation.test.docker.AllIT]:

Validation in the test method [spamReporting]
Check for [org.xwiki.invitation.test.po.InvitationGuestActionsPage] at http://xwikiweb:8080/xwiki/bin/view/Invitation/InvitationGuestActions?doAction_report=y&messageID=0009137086386838303154519655039602607834020330262119.

Form elements must have labels
Description: Ensures every form element has a label
Help URL: https://dequeuniversity.com/rules/axe/4.6/label?application=axeAPI
Help: Form elements must have labels
Impact: critical
Tags: cat.forms, wcag2a, wcag412, section508, section508.22.n, ACT

HTML element: 
    <input type="text" size="54" name="memo">
Selector: [input[size="54"]]
Fix any of the following:
  Form element does not have an implicit (wrapped) <label>
  Form element does not have an explicit <label>
  aria-label attribute does not exist or is empty
  aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
  Element has no title attribute
  Element has no placeholder attribute
  Element's default semantics were not overridden with role="none" or role="presentation"

Form elements must have labels
Description: Ensures every form element has a label
Help URL: https://dequeuniversity.com/rules/axe/4.6/label?application=axeAPI
Help: Form elements must have labels
Impact: critical
Tags: cat.forms, wcag2a, wcag412, section508, section508.22.n, ACT

HTML element: 
    <input checked="checked" name="messageID" type="checkbox" value="0009137086386838303154519655039602607834020330262119">
Selector: [input[name="messageID"]]
Fix any of the following:
  Form element does not have an implicit (wrapped) <label>
  Form element does not have an explicit <label>
  aria-label attribute does not exist or is empty
  aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
  Element has no title attribute
  Element has no placeholder attribute
  Element's default semantics were not overridden with role="none" or role="presentation"