Combobox: add option to open menu on focus

[max-sym]

Problem

Currently, combobox menu would only get open if:

• User starts typing into its input;
• User clicks on the combobox button.

I want to make it so that:

• Combobox menu opens up when I focus on the input;
• Whenever user selects an option it would NOT focus on its input again (I need to focus on the next field in the form right afterward, and currently it's being an issue to make it work cause it would focus on the former combobox input again)

Proposal

As an idea it could be to add 2 additional props:

• openOnFocus to Cobobox.Input;
• focusOnInputOnClose to Combobox.Option;

Both of them being boolean.

It can be split into 2 separate PRs.

Let me know what you think about it! :)
Thanks!