I18N: Add new WP_Locale::get_month_genitive() method.

Complements existing helper methods such as `WP_Locale::get_month_abbrev()`.

Props ankitkumarshah, Tkama, SergeyBiryukov.
Fixes #58658.

git-svn-id: https://develop.svn.wordpress.org/trunk@59494 602fd350-edb4-49c9-b593-d223f7449a82

Author: swissspidy

src/wp-includes/class-wp-locale.php

@@ -336,6 +336,26 @@ public function get_month_abbrev( $month_name ) {
 		return $this->month_abbrev[ $month_name ];
 	}
 
+	/**
+	 * Retrieves translated version of month genitive string.
+	 *
+	 * The $month_number parameter has to be a string
+	 * because it must have the '0' in front of any number
+	 * that is less than 10. Starts from '01' and ends at
+	 * '12'.
+	 *
+	 * You can use an integer instead and it will add the
+	 * '0' before the numbers less than 10 for you.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @param string|int $month_number '01' through '12'.
+	 * @return string Translated genitive month name.
+	 */
+	public function get_month_genitive( $month_number ) {
+		return $this->month_genitive[ zeroise( $month_number, 2 ) ];
+	}
+
 	/**
 	 * Retrieves translated version of meridiem string.
 	 *