Add transport endpoint URI helpers for all supported transports (#2502)

[BlackChepo]

Summary

Closes #2502

Adds a static <Transport>EndpointUri helper class to every supported transport package so users no longer have to hand-write raw URI strings when identifying endpoints.
Each helper exposes Uri-returning factory methods for every URI shape the transport's parser accepts, with consistent validation, XML docs, and URI-parser roundtrip tests.

Before:

options.PublishMessage<OrderCreated>()
       .ToUri(new Uri("rabbitmq://queue/orders"));

After:

options.PublishMessage<OrderCreated>()
       .ToUri(RabbitMqEndpointUri.Queue("orders"));

What's included

New helper classes (10 transports)

Package	Class	Methods
Wolverine.RabbitMQ	RabbitMqEndpointUri	Queue, Exchange, Topic(ex, key), Routing(ex, key)
Wolverine.Kafka	KafkaEndpointUri	Topic
Wolverine.AzureServiceBus	AzureServiceBusEndpointUri	Queue, Topic, Subscription(topic, sub)
Wolverine.AmazonSqs	SqsEndpointUri	Queue
Wolverine.AmazonSns	SnsEndpointUri	Topic
Wolverine.Redis	RedisEndpointUri	Stream, Stream(..., consumerGroup)
Wolverine.MQTT	MqttEndpointUri	Topic
Wolverine.Nats	NatsEndpointUri	Subject
Wolverine.Pulsar	PulsarEndpointUri	PersistentTopic, NonPersistentTopic, Topic(..., bool), Topic(string)
Wolverine.Pubsub	GcpPubsubEndpointUri	Topic(projectId, topicName)

Every method validates string inputs with ArgumentException.ThrowIfNullOrWhiteSpace and carries full XML documentation (<summary>, <param>, <returns>, <example>,
<exception>).

Migration of existing ad-hoc helpers

Two transports already shipped public URI builders. These are preserved with [Obsolete] attributes for backward compatibility:

Old	New	Migration
RedisTransport.BuildRedisStreamUri(...)	RedisEndpointUri.Stream(...)	One-line delegator. Obsolete.
PulsarEndpoint.UriFor(string topicPath)	PulsarEndpointUri.Topic(string)	One-line delegator. Obsolete.
PulsarEndpoint.UriFor(bool, tenant, ns, topic)	(no delegator)	Stays bit-exact. Obsolete. Returns a Pulsar-native topic path (persistent://...), which is a
different URI form from the Wolverine endpoint URI (pulsar://...) produced by PulsarEndpointUri. The obsolete message explains the non-delegation.

Internal library callers were rewritten where sensible:

• PulsarTransport.EndpointFor and PulsarTransportExtensions now call PulsarEndpointUri.Topic directly.
• PulsarListener's retry/DLQ topic builders still need the topic-path form for the native Pulsar client; those two call sites wrap the obsolete call with #pragma warning disable CS0618.

Behavioural note on PulsarEndpointUri.Topic(string)

The new canonical helper validates strictly: the input scheme must be persistent or non-persistent, and the path must contain exactly tenant/namespace/topic.
Previously-accepted malformed input (e.g. "http://..." or a Wolverine endpoint URI passed by mistake) now throws an ArgumentException at the helper instead of silently
producing a corrupt URI that only fails later in PulsarEndpoint.Parse. Callers passing well-formed Pulsar-native paths are unaffected.

Testing

• One new test class per transport (<Transport>EndpointUriTests.cs), covering shape assertions, null/whitespace validation theories, and — where feasible without a live
  broker — a URI-parser roundtrip via transport.GetOrCreateEndpoint(uri). ~130 test cases total.
• Additional compatibility tests in PulsarEndpointTests pin the deprecated UriFor behaviour:
  • uri_for_topic_string_handles_non_persistent_scheme
  • uri_for_topic_string_preserves_realistic_topic_names
  • uri_for_bool_produces_retry_suffix_path_used_by_pulsar_listener
  • uri_for_bool_produces_dlq_suffix_path_used_by_pulsar_listener

The last two lock down the exact URI format that PulsarListener passes to the native Pulsar client for retry and dead-letter topics, guarding against accidental
regressions in the interop-critical path.

Documentation

• Added a ## URI reference section to every transport's Vitepress page under docs/guide/messaging/transports/, with a table mapping URI forms to helper calls and a short
  C# sample.
• Redis and Pulsar pages carry a deprecation tip pointing users from BuildRedisStreamUri / UriFor to the new helpers.
• The Redis DocumentationSamples and four incidentally-using Pulsar test files (InlinePulsarTransportComplianceTests, PulsarTransportComplianceTests,
  WithCloudEvents, endpoint_configuration) were migrated to the new helper.

Breaking changes

None for source compatibility. The deprecated [Obsolete] attributes are warnings (not errors), and all call sites that passed well-formed input continue to work.

Test plan

• dotnet build wolverine.sln — 0 warnings, 0 errors from library code.
• Fast-test pass for every transport's *EndpointUriTests (all 10 classes green).
• Redis and Pulsar existing tests still pass (proves obsolete delegators preserve behaviour).
• Vitepress docs build picks up the new "URI reference" sections without layout regression.

[jeremydmiller]

@BlackChepo Thank you!