Select with Option filtering

### Select does not behave like Vue counterpart
When you click select with option filtering, the filter applied immedietly, making only 1 option available from the dropdown list.

### Reproduce Steps

1. go to https://elemefe.github.io/element-react/#/en-US/select
2. go to Option filtering section
3. select option3
4. Click to select a different option. Only option3 is listed.

A complete option should be available for user to select (like the one for vue).