docs(material/table): refactor table selection master toggle (#22647)

replace ternary operator by if statement with early return
replace redundant forEach statement with neat spread operator

(cherry picked from commit c46c49c)

Author: StanevichIvan

src/components-examples/material/table/table-selection/table-selection-example.ts

@@ -44,9 +44,12 @@ export class TableSelectionExample {
 
   /** Selects all rows if they are not all selected; otherwise clear selection. */
   masterToggle() {
-    this.isAllSelected() ?
-        this.selection.clear() :
-        this.dataSource.data.forEach(row => this.selection.select(row));
+    if (this.isAllSelected()) {
+      this.selection.clear();
+      return;
+    }
+
+    this.selection.select(...this.dataSource.data);
   }
 
   /** The label for the checkbox on the passed row */