Add ActionController and Swagger support

Updated `ReC.API.csproj` to include `Swashbuckle.AspNetCore` (v6.6.2) for Swagger/OpenAPI documentation. Removed an unused `<ItemGroup>` referencing the `Controllers\` folder.

Added a new `ActionController` with a `[Route("api/[controller]")]` and `[ApiController]` attributes. Introduced a `Trigger` HTTP POST endpoint that accepts a `profileId` parameter. The method is currently unimplemented and throws a `NotImplementedException`.

src/ReC.API/Controllers/ActionController.cs

@@ -0,0 +1,15 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace ReC.API.Controllers;
+
+[Route("api/[controller]")]
+[ApiController]
+public class ActionController : ControllerBase
+{
+    [HttpPost("{profileId}")]
+    public Task<IActionResult> Trigger([FromRoute] int profileId)
+    {
+        // Implementation for retrieving actions would go here.
+        throw new NotImplementedException();
+    }
+}

src/ReC.API/ReC.API.csproj

@@ -10,8 +10,4 @@
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Folder Include="Controllers\" />
-  </ItemGroup>
-
 </Project>