Request: Supports custom status types

[br14n-sol]

We should be able to pass our own state type to usePrefix as in the case of makeTheme.

This would be especially useful for those that use a state other than the one defined by inquirer, as in my case with inquirer-file-selector, which uses a state of its own to define when the user cancels the prompt.

[SBoudrias]

That's a reasonable request. PR welcomed is anyone gets to it before I do.