[fix] z-index for datepicker should be above grid row

frappe/public/css/desk.css

@@ -355,7 +355,7 @@ fieldset[disabled] .form-control {
 }
 /* jquery ui */
 .ui-datepicker {
-  z-index: 100 !important;
+  z-index: 9999 !important;
 }
 .ui-datepicker .ui-datepicker-header {
   border-radius: 0px !important;

frappe/public/less/desk.less

@@ -146,7 +146,7 @@ textarea.form-control {
 /* jquery ui */
 
 .ui-datepicker {
-	z-index: 100 !important;
+	z-index: 9999 !important;
 }
 
 .ui-datepicker .ui-datepicker-header {