Added rounded total in the POS and fix rounded issue in js side (#12457)

diff --git a/erpnext/public/css/pos.css b/erpnext/public/css/pos.css
index bc81182..e2d301d 100644
--- a/erpnext/public/css/pos.css
+++ b/erpnext/public/css/pos.css
@@ -169,5 +169,8 @@
   height: 60px;
 }
 .grand-total .grand-total-value {
-  font-size: 24px;
+  font-size: 18px;
+}
+.rounded-total-value {
+  font-size: 18px;
 }