Enhance documentation and introduce IReadQuery interface

Updated XML documentation in ConfigurationExtension.cs for better clarity.
Removed the old implementation and retained the functionality of GetOrDefault<T>.

Introduced a new IReadQuery<TEntity> interface in IReadQuery.cs,
providing methods for both asynchronous and synchronous entity queries,
along with comprehensive documentation for each method.

DigitalData.Core.Abstractions/ConfigurationExtension.cs

@@ -1,30 +1,29 @@
 using Microsoft.Extensions.Configuration;
 
-namespace DigitalData.Core.Abstractions
+namespace DigitalData.Core.Abstractions;
+
+/// <summary>
+/// Extension methods for the <see cref="IConfiguration"/> interface, providing 
+/// additional functionality for retrieving configuration values with default behavior.
+/// </summary>
+public static class ConfigurationExtension
 {
     /// <summary>
-    /// Extension methods for the <see cref="IConfiguration"/> interface, providing 
-    /// additional functionality for retrieving configuration values with default behavior.
+    /// Retrieves a configuration value for the specified key, or returns a default value 
+    /// of type <typeparamref name="T"/> if the configuration is not found or the key is null.
     /// </summary>
-    public static class ConfigurationExtension
-    {
-        /// <summary>
-        /// Retrieves a configuration value for the specified key, or returns a default value 
-        /// of type <typeparamref name="T"/> if the configuration is not found or the key is null.
-        /// </summary>
-        /// <typeparam name="T">The type of the object to retrieve from the configuration.</typeparam>
-        /// <param name="configuration">The <see cref="IConfiguration"/> instance.</param>
-        /// <param name="key">The optional key to look for in the configuration. If null, the method 
-        /// retrieves the root configuration.</param>
-        /// <returns>
-        /// An instance of <typeparamref name="T"/> populated from the configuration values, or 
-        /// a new instance of <typeparamref name="T"/> if no matching configuration is found.
-        /// </returns>
-        public static T GetOrDefault<T>(this IConfiguration configuration, string? key = null)
-            where T : new()
-            => (key is null
-                ? configuration.Get<T>()
-                : configuration.GetSection(key).Get<T>())
-            ?? new T();
-    }
+    /// <typeparam name="T">The type of the object to retrieve from the configuration.</typeparam>
+    /// <param name="configuration">The <see cref="IConfiguration"/> instance.</param>
+    /// <param name="key">The optional key to look for in the configuration. If null, the method 
+    /// retrieves the root configuration.</param>
+    /// <returns>
+    /// An instance of <typeparamref name="T"/> populated from the configuration values, or 
+    /// a new instance of <typeparamref name="T"/> if no matching configuration is found.
+    /// </returns>
+    public static T GetOrDefault<T>(this IConfiguration configuration, string? key = null)
+        where T : new()
+        => (key is null
+            ? configuration.Get<T>()
+            : configuration.GetSection(key).Get<T>())
+        ?? new T();
 }