[Form] Feature Request: name/ID field for checkboxes

### Impacted plugin

Jetpack

### What

The ability to set name/ID for checkbox fields inside the Form block.

### How

The checkbox form field block should have the same name/ID field under Advanced:

This will allow greater expandability and integrations for the Jetpack Form.

Start at the Jetpack Form block's checkbox field and its Advanced settings, then trace how the existing name/ID field is handled for other form fields. The work is done when checkbox fields expose the same setting and the value is available for integrations.

Written by the indexing model from the issue text.