Code style - Use file scoped namespaces

Code style - Ran code cleanup

src/Artemis.Core/Services/Interfaces/IPluginService.cs

@@ -1,13 +1,12 @@
-namespace Artemis.Core.Services
+namespace Artemis.Core.Services;
+
+/// <summary>
+///     An interface for services provided by plugins.
+///     <para>
+///         Any service implementing this interface will be available inside the plugin as a singleton through dependency
+///         injection
+///     </para>
+/// </summary>
+public interface IPluginService
 {
-    /// <summary>
-    ///     An interface for services provided by plugins.
-    ///     <para>
-    ///         Any service implementing this interface will be available inside the plugin as a singleton through dependency
-    ///         injection
-    ///     </para>
-    /// </summary>
-    public interface IPluginService
-    {
-    }
 }