fix: Empty row is cliable in FluentDataGrid

[JamesNK]

🐛 Bug Report

💻 Repro or Code Sample

Empty grid row template is displayed like it is clickable (has hover color, pointer cursor) and clicking on it triggers OnRowClick.

Also, it has an odd mix of attributes:

🤔 Expected Behavior

Regular, non-clickable row

😯 Current Behavior

Clickable

💁 Possible Solution

🔦 Context

🌍 Your Environment

• OS & Device: [e.g. MacOS, iOS, Windows, Linux] on [iPhone 7, PC]
• Browser [e.g. Microsoft Edge, Google Chrome, Apple Safari, Mozilla FireFox]
• .NET and Fluent UI Blazor library Version [e.g. 8.0.2 and 4.4.1]