Show progress bar as pending while wiki is being built

This ability was added upstream for this use case.

Author: edg2s

new.js

@@ -6,6 +6,8 @@
 		document.getElementsByClassName( 'installProgressField' )[ 0 ]
 	);
 
+	pd.installProgressField.fieldWidget.pushPending();
+
 	pd.openWiki = OO.ui.infuse(
 		document.getElementsByClassName( 'openWiki' )[ 0 ]
 	);

new.php

@@ -23,6 +23,7 @@ function abandon( $err ) {
 	echo <<<EOT
 		<script>
 			pd.installProgressField.fieldWidget.setDisabled( true );
+			pd.installProgressField.fieldWidget.popPending();
 			pd.installProgressField.setErrors( [ $errJson ] );
 		</script>
 EOT;
@@ -42,6 +43,7 @@ function set_progress( int $pc, string $label ) {
 	if ( $pc === 100 ) {
 		echo <<<EOT
 		<script>
+			pd.installProgressField.fieldWidget.popPending();
 			pd.openWiki.setDisabled( false );
 		</script>
 EOT;