Place search box in the countries list

[alybarreno]

Describe the bug:
The list of countries is very long, you should place a search box at the beginning to facilitate the search. In addition, the list of states related to the selected country must be loaded in the status field.

To Reproduce:

1. Create a form with the country field
2. Publish the form
3. Open country list
4. Visualize that it is very long

Expected behavior:

• The "country" field must have a search engine.
• When selecting a country, its states must be shown in the "status" field.

Screenshots: