Support HTTP method-restricted interceptors in InterceptorRegistration

This PR implements #35272, adding support for restricting HandlerInterceptor registration to specific HTTP methods.

Motivation

Spring MVC currently allows interceptors to be applied based on path patterns, but not HTTP methods. When method-based filtering is needed, it must be manually implemented within the interceptor itself:

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
    if (!"POST".equals(request.getMethod())) {
        return true;
    }
    // Logic here
    return true;
}

This approach clutters interceptor logic with method checks and duplicates similar logic across interceptors when needed. Centralizing HTTP method filtering in the registration API provides a cleaner and more declarative configuration style.

Solution

This PR introduces a new method to InterceptorRegistration:

public InterceptorRegistration allowedMethods(HttpMethod... methods)

This allows restricting the interceptor to specific HTTP methods like GET, POST, etc. Under the hood, the framework wraps the given HandlerInterceptor in a new MethodInterceptor that delegates calls only when the request's HTTP method matches one of the allowed methods.

registry.addInterceptor(new MyInterceptor())
        .addPathPatterns("/api/**")
        .allowedMethods(HttpMethod.POST, HttpMethod.PUT);

The interceptor will now be invoked only for POST and PUT requests matching /api/**.

Implementation Details

• InterceptorRegistration stores allowed HTTP methods as a Set<String>.
• If any methods are configured, it wraps the given interceptor using the new MethodInterceptor.
• MethodInterceptor checks the request's method before delegating to the original interceptor.
• The implementation is fully backward compatible; if no methods are provided, all HTTP methods are allowed (default behavior).

Tests

A dedicated test class MethodInterceptorTests is included to validate:

• Delegation occurs only for allowed HTTP methods.
• Interceptor is skipped for disallowed methods.
• All interceptor lifecycle methods (preHandle, postHandle, afterCompletion) are covered.

Example

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new AuditInterceptor())
                .addPathPatterns("/admin/**")
                .allowedMethods(HttpMethod.GET);
    }
}

In this example, AuditInterceptor will apply only for GET requests under /admin/**.

Compatibility

• No breaking changes introduced.
• The feature is opt-in.
• Reuses existing Spring MVC components (MappedInterceptor, HandlerInterceptor) without exposing new public types.