Added support for formatted text in the select message

[kotazzz]

What is the problem that this PR addresses?
Currently, the message parameter of questionary.select() only accepts plain strings and does not support formatted text (e.g., ANSI or Rich styles).
This makes it impossible to style the prompt title, even though option titles (choices) already support formatting via FormattedText.

Closes #449
Related to #107

How did you solve it?
I extended the logic in select() so that the message parameter now accepts FormattedText (including objects with __pt_formatted_text__ or lists of style/text tuples).
If a formatted message is provided, it is rendered with all styles and colors preserved, just like for option titles.
This was tested with both manual ANSI codes and Rich → PromptToolkit conversions to confirm correct rendering.

Checklist

• I have read the Contributor's Guide.
• I have checked that all automated PR checks pass before requesting review.

[kotazzz]

@tmbo Hi! This PR fixes #449. Could you take a look when you have a chance?