fix: set title attribute for grid header columns

frappe/public/js/frappe/form/grid_row.js

@@ -316,6 +316,12 @@ export default class GridRow {
 
 		$col.field_area = $('<div class="field-area"></div>').appendTo($col).toggle(false);
 		$col.static_area = $('<div class="static-area ellipsis"></div>').appendTo($col).html(txt);
+
+		// set title attribute to see full label for columns in the heading row
+		if (!this.doc) {
+			$col.attr("title", txt);
+		}
+
 		$col.df = df;
 		$col.column_index = ci;