fix: bind-SelectedOption is null when using bind-SelectedOption:after FluentComboBox

[MarvinKlein1508]

🐛 Bug Report

When using a FluentComboBox in combination with bind-SelectedOption:after the binded option will be set null when using a different instance of the bound object type which is not part of the Items parameter.

💻 Repro or Code Sample

I've created a small sample repo which can be found here:
https://github.com/MarvinKlein1508/FluentComboBoxIssue

🤔 Expected Behavior

I would expect the component to select the item with the corresponding CountryId since both of them are the same.

😯 Current Behavior

The component sets the value to null.

🔦 Context

In my case I'm using a static list of countries in memory which contains all possible countries. However when fetching the object from the database a new instance is assigned to my object based on the provided SQL query.

🌍 Your Environment

.NET 8 with Firefox. VS17.10.0