Add Polly resilience policies

clients/dotnet/MxGateway.Client/MxGatewayClientRetryOptions.cs

@@ -0,0 +1,43 @@
+namespace MxGateway.Client;
+
+public sealed class MxGatewayClientRetryOptions
+{
+    public int MaxAttempts { get; init; } = 2;
+
+    public TimeSpan Delay { get; init; } = TimeSpan.FromMilliseconds(200);
+
+    public TimeSpan MaxDelay { get; init; } = TimeSpan.FromSeconds(2);
+
+    public bool UseJitter { get; init; } = true;
+
+    public void Validate()
+    {
+        if (MaxAttempts <= 0)
+        {
+            throw new ArgumentOutOfRangeException(
+                nameof(MaxAttempts),
+                "The retry max attempts value must be greater than zero.");
+        }
+
+        if (Delay <= TimeSpan.Zero)
+        {
+            throw new ArgumentOutOfRangeException(
+                nameof(Delay),
+                "The retry delay must be greater than zero.");
+        }
+
+        if (MaxDelay <= TimeSpan.Zero)
+        {
+            throw new ArgumentOutOfRangeException(
+                nameof(MaxDelay),
+                "The retry max delay must be greater than zero.");
+        }
+
+        if (MaxDelay < Delay)
+        {
+            throw new ArgumentOutOfRangeException(
+                nameof(MaxDelay),
+                "The retry max delay must be greater than or equal to the retry delay.");
+        }
+    }
+}