Add TryGetPrimaryDepartment to jobs system (#23317)

* add primary departments

* make command and station specific secondary

* add a unit test

* fixy

* compile

* webedit ops

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.IntegrationTests/Tests/Minds/JobTests.cs

@@ -0,0 +1,48 @@
+using Content.Shared.Roles;
+using Content.Shared.Roles.Jobs;
+using Robust.Shared.Prototypes;
+using System.Linq;
+
+namespace Content.IntegrationTests.Tests.Station;
+
+[TestFixture]
+[TestOf(typeof(SharedJobSystem))]
+public sealed class JobTest
+{
+    /// <summary>
+    /// Ensures that every job belongs to at most 1 primary department.
+    /// Having no primary department is ok.
+    /// </summary>
+    [Test]
+    public async Task PrimaryDepartmentsTest()
+    {
+        await using var pair = await PoolManager.GetServerClient();
+        var server = pair.Server;
+
+        var prototypeManager = server.ResolveDependency<IPrototypeManager>();
+
+        await server.WaitAssertion(() =>
+        {
+            // only checking primary departments so don't bother with others
+            var departments = prototypeManager.EnumeratePrototypes<DepartmentPrototype>()
+                .Where(department => department.Primary)
+                .ToList();
+            var jobs = prototypeManager.EnumeratePrototypes<JobPrototype>();
+            foreach (var job in jobs)
+            {
+                // not actually using the jobs system since that will return the first department
+                // and we need to test that there is never more than 1, so it not sorting them is correct
+                var primaries = 0;
+                foreach (var department in departments)
+                {
+                    if (!department.Roles.Contains(job.ID))
+                        continue;
+
+                    primaries++;
+                    Assert.That(primaries, Is.EqualTo(1), $"The job {job.ID} has more than 1 primary department!");
+                }
+            }
+        });
+        await pair.CleanReturnAsync();
+    }
+}