[TASK] Viewhelper/Templates cleanup for escaped content

Classes/ViewHelpers/AbstractViewHelper.php

Classes/ViewHelpers/Backend/ControlViewHelper.php

Classes/ViewHelpers/Backend/EditOnClickViewHelper.php

Classes/ViewHelpers/Backend/IconViewHelper.php

Classes/ViewHelpers/Widget/UriViewHelper.php

Resources/Private/Templates/Mail/Index.html

Resources/Private/Templates/Queue/Index.html

.../Templates/ViewHelpers/Backend/Widget/Paginate/Index.html