refactor: allow for concurrent use of reconciliation tool

1. set default filter dates a period of one month from current date
diff --git a/erpnext/accounts/doctype/bank_reconciliation_tool/bank_reconciliation_tool.js b/erpnext/accounts/doctype/bank_reconciliation_tool/bank_reconciliation_tool.js
index 22d3335..d977261 100644
--- a/erpnext/accounts/doctype/bank_reconciliation_tool/bank_reconciliation_tool.js
+++ b/erpnext/accounts/doctype/bank_reconciliation_tool/bank_reconciliation_tool.js
@@ -18,6 +18,10 @@
 	},
 
 	onload: function (frm) {
+		// Set default filter dates
+		today = frappe.datetime.get_today()
+		frm.doc.bank_statement_from_date = frappe.datetime.add_months(today, -1);
+		frm.doc.bank_statement_to_date = today;
 		frm.trigger('bank_account');
 	},
 
@@ -32,6 +36,7 @@
 	},
 
 	refresh: function (frm) {
+		frm.disable_save();
 		frappe.require("bank-reconciliation-tool.bundle.js", () =>
 			frm.trigger("make_reconciliation_tool")
 		);
@@ -73,10 +78,11 @@
 			})
 		});
 
-	},
+		frm.add_custom_button(__('Get Unreconciled Entries'), function() {
+			frm.trigger("make_reconciliation_tool");
+		});
+		frm.change_custom_button_type('Get Unreconciled Entries', null, 'primary');
 
-	after_save: function (frm) {
-		frm.trigger("make_reconciliation_tool");
 	},
 
 	bank_account: function (frm) {