Add label and switch ocdialog close button to button element

Signed-off-by: Christopher Ng <chrng8@gmail.com>
Signed-off-by: nextcloud-command <nextcloud-command@users.noreply.github.com>

Author: Pytal

core/src/jquery/css/jquery.ocdialog.scss

@@ -50,8 +50,10 @@
 
 .oc-dialog-close {
 	position: absolute;
-	top: 0;
-	right: 0;
+	width: 44px !important;
+	height: 44px !important;
+	top: 4px;
+	right: 4px;
 	padding: 25px;
 	background: var(--icon-close-dark) no-repeat center;
 	opacity: .5;

core/src/jquery/ocdialog.js

@@ -177,7 +177,8 @@ $.widget('oc.ocdialog', {
 			break
 		case 'closeButton':
 			if (value) {
-				const $closeButton = $('<a class="oc-dialog-close" tabindex="0"></a>')
+				const $closeButton = $('<button class="oc-dialog-close"></button>')
+				$closeButton.attr('aria-label', t('core', 'Close "{dialogTitle}" dialog', { dialogTitle: this.$title || this.options.title }))
 				this.$dialog.prepend($closeButton)
 				$closeButton.on('click keydown', function(event) {
 					if (isA11yActivation(event)) {