Implement temporary file configuration endpoint (#15518)

* Implement temporary file configuration endpoint

* Update MaxfileSize to be a string.

* Make max file size a nullable integer

---------

Co-authored-by: Elitsa <elm@umbraco.dk>

src/Umbraco.Cms.Api.Management/Controllers/TemporaryFile/ConfigurationTemporaryFileController.cs

@@ -0,0 +1,26 @@
+using Asp.Versioning;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Umbraco.Cms.Api.Management.Factories;
+using Umbraco.Cms.Api.Management.ViewModels.TemporaryFile;
+
+namespace Umbraco.Cms.Api.Management.Controllers.TemporaryFile;
+
+[ApiVersion("1.0")]
+public class ConfigurationTemporaryFileController : TemporaryFileControllerBase
+{
+    private readonly ITemporaryFileConfigurationPresentationFactory _temporaryFileConfigurationPresentationFactory;
+
+    public ConfigurationTemporaryFileController(
+        ITemporaryFileConfigurationPresentationFactory temporaryFileConfigurationPresentationFactory) =>
+        _temporaryFileConfigurationPresentationFactory = temporaryFileConfigurationPresentationFactory;
+
+    [HttpGet("configuration")]
+    [MapToApiVersion("1.0")]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    public Task<IActionResult> Configuration()
+    {
+        TemporaryFileConfigurationResponseModel responseModel = _temporaryFileConfigurationPresentationFactory.Create();
+        return Task.FromResult<IActionResult>(Ok(responseModel));
+    }
+}