[PM-14439] Add PolicyRequirementQuery for enforcement logic (#5336)

* Add PolicyRequirementQuery, helpers and models in preparation for migrating domain code

Co-authored-by: Rui Tomé <108268980+r-tome@users.noreply.github.com>

test/Core.Test/AdminConsole/OrganizationFeatures/Policies/PolicyRequirementQueryTests.cs

@@ -0,0 +1,60 @@
+using Bit.Core.AdminConsole.Models.Data.Organizations.Policies;
+using Bit.Core.AdminConsole.OrganizationFeatures.Policies.Implementations;
+using Bit.Core.AdminConsole.OrganizationFeatures.Policies.PolicyRequirements;
+using Bit.Core.AdminConsole.Repositories;
+using Bit.Test.Common.AutoFixture.Attributes;
+using NSubstitute;
+using Xunit;
+
+namespace Bit.Core.Test.AdminConsole.OrganizationFeatures.Policies;
+
+[SutProviderCustomize]
+public class PolicyRequirementQueryTests
+{
+    /// <summary>
+    /// Tests that the query correctly registers, retrieves and instantiates arbitrary IPolicyRequirements
+    /// according to their provided CreateRequirement delegate.
+    /// </summary>
+    [Theory, BitAutoData]
+    public async Task GetAsync_Works(Guid userId, Guid organizationId)
+    {
+        var policyRepository = Substitute.For<IPolicyRepository>();
+        var factories = new List<RequirementFactory<IPolicyRequirement>>
+        {
+            // In prod this cast is handled when the CreateRequirement delegate is registered in DI
+            (RequirementFactory<TestPolicyRequirement>)TestPolicyRequirement.Create
+        };
+
+        var sut = new PolicyRequirementQuery(policyRepository, factories);
+        policyRepository.GetPolicyDetailsByUserId(userId).Returns([
+            new PolicyDetails
+            {
+                OrganizationId = organizationId
+            }
+        ]);
+
+        var requirement = await sut.GetAsync<TestPolicyRequirement>(userId);
+        Assert.Equal(organizationId, requirement.OrganizationId);
+    }
+
+    [Theory, BitAutoData]
+    public async Task GetAsync_ThrowsIfNoRequirementRegistered(Guid userId)
+    {
+        var policyRepository = Substitute.For<IPolicyRepository>();
+        var sut = new PolicyRequirementQuery(policyRepository, []);
+
+        var exception = await Assert.ThrowsAsync<NotImplementedException>(()
+            => sut.GetAsync<TestPolicyRequirement>(userId));
+        Assert.Contains("No Policy Requirement found", exception.Message);
+    }
+
+    /// <summary>
+    /// Intentionally simplified PolicyRequirement that just holds the Policy.OrganizationId for us to assert against.
+    /// </summary>
+    private class TestPolicyRequirement : IPolicyRequirement
+    {
+        public Guid OrganizationId { get; init; }
+        public static TestPolicyRequirement Create(IEnumerable<PolicyDetails> policyDetails)
+            => new() { OrganizationId = policyDetails.Single().OrganizationId };
+    }
+}