Add Marking Localization Test (DeltaV-Station#1421)

# Description

Actual localization strings added in different PR.

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<details><summary><h1>Media</h1></summary>
<p>


![image](https://github.com/user-attachments/assets/cca4ae17-f75b-4c1a-8137-564a410e4563)

</p>
</details>

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Co-authored-by: sleepyyapril <123355664+sleepyyapril@users.noreply.github.com>

Content.IntegrationTests/Tests/Markings/MarkingLocalizationTest.cs

@@ -0,0 +1,38 @@
+using Robust.Shared.Prototypes;
+using Robust.Shared.Localization;
+using Content.Shared.Humanoid.Markings;
+using System.Linq;
+using System.Collections.Generic;
+
+namespace Content.IntegrationTests.Tests.Traits;
+
+/// <summary>
+///    Checks if every marking has a valid name localization string.
+/// </summary>
+[TestFixture]
+[TestOf(typeof(MarkingPrototype))]
+public sealed class MarkingLocalizationTest
+{
+    [Test]
+    public async Task TestMarkingLocalization()
+    {
+        await using var pair = await PoolManager.GetServerClient();
+        var server = pair.Server;
+
+        var locale = server.ResolveDependency<ILocalizationManager>();
+        var proto = server.ResolveDependency<IPrototypeManager>();
+
+        await server.WaitAssertion(() =>
+        {
+            var missingStrings = new List<string>();
+
+            foreach (var markingProto in proto.EnumeratePrototypes<MarkingPrototype>().OrderBy(a => a.ID))
+                if (!locale.HasString($"marking-{markingProto.ID}") && string.IsNullOrEmpty(markingProto.Name))
+                    missingStrings.Add($"\"{markingProto.ID}\", \"marking-{markingProto.ID}\"");
+
+            Assert.That(!missingStrings.Any(), Is.True, $"The following markings are missing localization strings:\n  {string.Join("\n  ", missingStrings)}");
+        });
+
+        await pair.CleanReturnAsync();
+    }
+}