Add HttpGet endpoint to OutResController for data retrieval

Added a new asynchronous `Get` method to the `OutResController`
class in the `ReC.API.Controllers` namespace. This method handles
HTTP GET requests, accepts a `ReadOutResQuery` object as a query
parameter, and uses the `mediator` to process the query. The
result is returned in an HTTP 200 OK response. This change
enables retrieval of resources or data based on the provided
query parameters.

src/ReC.API/Controllers/OutResController.cs

@@ -8,5 +8,6 @@ namespace ReC.API.Controllers;
 [ApiController]
 public class OutResController(IMediator mediator) : ControllerBase
 {
+    [HttpGet]
     public async Task<IActionResult> Get([FromQuery] ReadOutResQuery query) => Ok(await mediator.Send(query));
 }