add: download and import user template xlsx

app/imports/admins/new_import_user_from_excel.rb

@@ -0,0 +1,15 @@
+class Admins::NewImportUserFromExcel < BaseImportXlsx
+  UserData = Struct.new(:login, :email, :password, :nickname)
+
+  def read_each(&block)
+    sheet.each_row_streaming(pad_cells: true, offset: 1) do |row|
+      data = row.map(&method(:cell_value))[0..3]
+      block.call UserData.new(*data)
+    end
+  end
+
+  private 
+  def cell_value(obj)
+    obj&.cell_value 
+  end
+end