Add the Accept-Query header constant

Author: desiderantes

httpcore5/src/main/java/org/apache/hc/core5/http/HttpHeaders.java

@@ -48,6 +48,13 @@ private HttpHeaders() {
 
     public static final String ACCEPT_RANGES = "Accept-Ranges";
 
+    /**
+     * The RFC 10008 {@code Accept-Query} response header field name.
+     *
+     * @since 5.5
+     */
+    public static final String ACCEPT_QUERY = "Accept-Query";
+
     /**
      * The CORS {@code Access-Control-Allow-Credentials} response header field name.
      */