feat: add multi-threaded evaluation benchmark suite with comprehensive C# implementation (#457)

This commit introduces a complete multi-threaded evaluation benchmark suite for both Rust and C# implementations of Regorus.

- Implemented engine evaluation benchmark with input and engine cloning strategies
- Implemented compiled policy evaluation benchmark with input cloning and shared compiled policy strategies.

- Created EngineEvaluationBenchmark.cs and CompiledPolicyEvaluationBenchmark.cs with time-based execution (3s warmup + 3s evaluation)
- Implemented configuration options matching Rust implementation (useClonedEngines, useSharedPolicies parameters)

- Created markdown analysis documentation with cross-platform performance analysis
- C# seems to achieve 58-89% of Rust performance on test machine.

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

benches/evaluation/test_data/inputs/azure_nsg_input.json

@@ -0,0 +1,13 @@
+{
+  "operation": "Microsoft.Network/networkSecurityGroups/securityRules/write",
+  "rule": {
+    "direction": "Inbound",
+    "access": "Allow",
+    "protocol": "TCP",
+    "sourceAddressPrefix": "10.0.0.0/24",
+    "sourcePortRange": "*",
+    "destinationAddressPrefix": "*",
+    "destinationPortRange": "80",
+    "priority": 1001
+  }
+}