Add SearchHighlightStyle method to SelectionPromptExtensions

[fihorvat]

fixes #

• I have read the Contribution Guidelines
• I have commented on the issue above and discussed the intended changes
• A maintainer has signed off on the changes and the issue was assigned to me
• All newly added code is adequately covered by tests
• All existing tests are still running without errors
• The documentation was modified to reflect the changes OR no documentation changes are required.

Changes

I added the extension method for defining SearchHighlightStyle same as we have for HighlightStyle.

This allows us to specify SearchHighlightStyle using a fluent style like this:

AnsiConsole.Prompt(
  new SelectionPrompt<CustomSelectionItem>()
    .Title("Select one")
    .EnableSearch()
    .UseConverter(o => o.Name)
    .HighlightStyle(Color.Green)
    .SearchHighlightStyle(Color.DarkGreen) //<--
    .AddChoices(choices));

---

Please upvote 👍 this pull request if you are interested in it.

[fihorvat]

@microsoft-github-policy-service agree