Refactored HTTP method handling by introducing a `ToHttpMethod`
extension method in `HttpExtensions.cs` to convert string
representations of HTTP methods to `HttpMethod` objects.
Replaced manual `HttpMethod` instantiation with the new
extension method in `InvokeRecActionCommandHandler` for
improved readability and reusability.
Removed unused `using` directives from `HttpExtensions.cs`
and cleaned up the `namespace` declaration. Added a `using`
directive for `ReC.Application.Common` in
`InvokeRecActionCommand.cs` to support the new extension method.
Updated `InvokeRecActionCommand.cs` to use `using` statements for `HttpClient`, `HttpRequestMessage`, and `HttpResponseMessage` to prevent resource leaks.
Added a new `HttpExtensions.cs` file with a static `HttpExtensions` class as a placeholder for future HTTP-related extension methods. Included necessary `using` directives for potential LINQ, collections, and asynchronous programming.
