Components: Set a default for the ComboboxControl onFilterValueChange

[pablinos]

Description

While using the the ComboboxControl I noticed that there were errors stating that onFilterValueChange was undefined. Looking at the example in Storybook, it seems that this was probably required in the past, and was a way for the logic of how the suggestions are filtered, to be handled outside of the combobox.

This can safely be set to a no-op function and the control works as expected. This PR sets that as the default and updates the Storybook example so that it shows the simplified usage.

How has this been tested?

This has been manually tested, in the block I'm developing and using Storybook. The frontend functionality remains unchanged.

Types of changes

This should probably be categorised as a bug fix. The onFilterValueChange prop can be optional, but would cause an error if omitted.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[sarayourfriend]

LGTM, just one change request and it'll be all set 😁

[sarayourfriend]

LGTM! Thanks!

[retrofox]

@sarayourfriend could you take a look at this super small one, please?