feat: Complete target system with C# bindings and resource inference (#458)

* feat: Add Schema Registry and Validation Framework

This commit introduces a comprehensive schema registry and validation framework, providing schema-based validation of resources and policy effects.

- Thread-safe, in-memory registry for schema storage and management
- Global registry patterns for effects and resources
- Concurrent access with proper error handling
- Unicode schema names support

- JSON Schema-compliant validation for all primitive types
- Advanced constraint validation (patterns, ranges, length limits)
- Discriminated union support with anyOf schemas
- Detailed error reporting with nested validation paths
- Discriminated subobject validation for polymorphic schemas

- **Registry Tests**: All registry operations
- **Effect Tests**: Policy effect validation
- **Resource Tests**: Resource validation
- **Validation Tests**: Core validation engine
- Thread-safety, error handling, integration scenarios, edge cases

- **Dependencies**: dashmap, once_cell, regex
- **Thread Safety**: Minimal locking with Rc<Schema> sharing
- **Error Types**: TypeMismatch, OutOfRange, PatternMismatch, etc.

- Complete schema registry and validation subsystem
- Comprehensive test coverage
- Foundation for policy validation in Regorus

Benchmarks:

- Criterion benchmarks for basic types, effects and Azure resources
- Performance range: 3.22ns (string) to 34.74µs (Azure VM resource schema validation)
- String withs patterns validation: 30.2µs. Need to explore whether regex caching helps
  bring this down.
- Azure policy effects: 188ns-1.4µs

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

* feat: Complete target system with C# bindings and resource inference

- Add comprehensive target system with TargetRegistry and target-aware compilation
- Implement resource type inference from policy equality expressions
- Create modular C# bindings with separate wrapper classes for each concept
- Add thread-safe CompiledPolicy with reference counting for safe disposal
- Enhance FFI with detailed error propagation and target functionality
- Create TargetExampleApp demonstrating Azure Policy integration
- Add CI/CD pipeline testing for all C# applications
- Support target definitions with schema validation and resource selectors
- Implement PolicyModule struct and target-aware compilation methods
- Add comprehensive test coverage for target functionality

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

---------

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

bindings/c/main.c

@@ -8,43 +8,43 @@ int main() {
 
     // Turn on rego v0 since policy uses v0.
     r = regorus_engine_set_rego_v0(engine, true);
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
 
     // Load policies.
     r = regorus_engine_add_policy_from_file(engine, "../../../tests/aci/framework.rego");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
     printf("Loaded package %s\n", r.output);
     regorus_result_drop(r);
 
     r = regorus_engine_add_policy_from_file(engine, "../../../tests/aci/api.rego");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
     printf("Loaded package %s\n", r.output);
     regorus_result_drop(r);
     
     r = regorus_engine_add_policy_from_file(engine, "../../../tests/aci/policy.rego");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
     printf("Loaded package %s\n", r.output);
     regorus_result_drop(r);
 
     // Add data
     r = regorus_engine_add_data_from_json_file(engine, "../../../tests/aci/data.json");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
     regorus_result_drop(r);
 
     // Set input
     r = regorus_engine_set_input_from_json_file(engine, "../../../tests/aci/input.json");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
     regorus_result_drop(r);
 
     // Eval rule.
     r = regorus_engine_eval_query(engine, "data.framework.mount_overlay");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
 
     // Print output
@@ -66,14 +66,14 @@ int main() {
 	);
 
     // Evaluate rule.
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
 
     r = regorus_engine_set_enable_coverage(engine, true);
     regorus_result_drop(r);
     
     r = regorus_engine_eval_query(engine, "data.test.message");
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
 
     // Print output
@@ -82,7 +82,7 @@ int main() {
 	
     // Print pretty coverage report.
     r = regorus_engine_get_coverage_report_pretty(engine);
-    if (r.status != RegorusStatusOk)
+    if (r.status != Ok)
 	goto error;
 
     printf("%s\n", r.output);