use raw query in hollow ui http handler

Previously, parsing post data from the request URI query string would
decode sequences twice, first in `getQuery()`, then in `parseQueryString`.
This would cause `'+'` characters to be converted to whitespace.

Fix this by using `getRawQuery()` instead.

Author: kvoli

hollow-ui-tools/src/main/java/com/netflix/hollow/ui/HttpHandlerWithServletSupport.java

@@ -305,7 +305,7 @@ public void setReadListener(ReadListener readListener) {
         Map<String, String[]> parsePostData = new HashMap<>();
 
         try {
-            parsePostData.putAll(HttpUtils.parseQueryString(ex.getRequestURI().getQuery()));
+            parsePostData.putAll(HttpUtils.parseQueryString(ex.getRequestURI().getRawQuery()));
 
             // check if any postdata to parse
             parsePostData.putAll(HttpUtils.parsePostData(inBytes.length, is));