Enable parallelism in test projects

[rbev]

This pull request introduces several improvements to the test infrastructure to introduce parallelisation within the test projects to improve CI build times.

Test Infrastructure and Parallelization Enhancements:

• Added global NUnit settings (FixtureLifeCycle, Parallelizable, and LevelOfParallelism) to both src/Particular.LicensingComponent.UnitTests/NUnitSettings.cs and src/ServiceControl.AcceptanceTests.RavenDB/NUnitSettings.cs to enable test parallelization and control concurrency level.
• Introduced a SetupFixture in src/ServiceControl.AcceptanceTests.RavenDB/SetupFixture.cs to ensure required event log sources are created before tests run, preventing race conditions during test startup.
• Added a static SemaphoreSlim-based lock and UseDatabaseLifecycleLock method in AcceptanceTestStorageConfiguration to serialize database lifecycle operations, preventing parallel access issues with the shared RavenDB server.

Test Safety and Reliability:

• Marked tests that interact with shared resources (e.g., CORS, forwarded headers, critical errors, message import failures) as [NonParallelizable] to avoid race conditions and ensure reliable test execution.

Groups with full parallelism

Group	Test Projects
AzureStorageQueues	ServiceControl.Transports.ASQ.Tests
Default	ServiceControl.Audit.AcceptanceTests, ServiceControl.Audit.AcceptanceTests.RavenDB (linked NUnitSettings.cs from Audit.AcceptanceTests), ServiceControl.Audit.Persistence.Tests, ServiceControl.Audit.Persistence.Tests.RavenDB (linked NUnitSettings.cs from Audit.Persistence.Tests), ServiceControl.Audit.UnitTests, ServiceControl.Config.Tests, ServiceControl.Infrastructure.Tests, ServiceControlInstaller.Engine.UnitTests, ServiceControlInstaller.Packaging.UnitTests, ServiceControl.Monitoring.AcceptanceTests, ServiceControl.Monitoring.UnitTests, ServiceControl.MultiInstance.AcceptanceTests, ServiceControl.Persistence.Tests.InMemory, ServiceControl.Transports.Tests, ServiceControl.UnitTests, Particular.LicensingComponent.UnitTests
IBMMQ	ServiceControl.Transports.IBMMQ.Tests
PostgreSQL	ServiceControl.Transports.PostgreSql.Tests
PostgreSQLPersistence	ServiceControl.Persistence.Tests.PostgreSql
PrimaryRavenAcceptance	ServiceControl.AcceptanceTests.RavenDB
PrimaryRavenPersistence	ServiceControl.Persistence.Tests.RavenDB
SqlServerPersistence	ServiceControl.Persistence.Tests.SqlServer

Groups not updated

Group	Test Projects
AzureServiceBus	ServiceControl.Transports.ASBS.Tests
MSMQ	ServiceControl.Transports.Msmq.Tests
RabbitMQ	ServiceControl.Transports.RabbitMQClassicConventionalRouting.Tests, ServiceControl.Transports.RabbitMQClassicDirectRouting.Tests, ServiceControl.Transports.RabbitMQQuorumConventionalRouting.Tests, ServiceControl.Transports.RabbitMQQuorumDirectRouting.Tests
SQS	ServiceControl.Transports.SQS.Tests
SqlServer	ServiceControl.Transports.SqlServer.Tests

[johnsimons]

Should we just use the default for LevelOfParallelism https://docs.nunit.org/articles/nunit/writing-tests/attributes/levelofparallelism.html, which mean not using the attribute?

[rbev]

Should we just use the default for LevelOfParallelism https://docs.nunit.org/articles/nunit/writing-tests/attributes/levelofparallelism.html, which mean not using the attribute?

I removed the explicit setting and it ran much slower, the build agents don't have 4 cores and benefit from having higher parallelism.