MudComboBox: Change SetText Behavior at the Start of Lifecycle (#601)

* Fix: Use `_firstRendered` to conditionally update input text in `MudComboBox`, prevents StateHasChanged called before component is fully initialized.

* Add More Proper Fix

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Co-authored-by: Mehmet Can Karagöz <m.cankaragoz@outlook.com>

Author: purepvd

src/CodeBeam.MudBlazor.Extensions/Components/ComboBox/MudComboBox.razor.cs

@@ -812,7 +812,7 @@ protected override async Task OnParametersSetAsync()
                     _searchString = ConvertSet(ReadValue);
                     if (_inputReference != null)
                     {
-                        await _inputReference?.SetText(_searchString);
+                        await SetTextCoreAsync(_searchString);
                     }
                 }
             }