Update Client.connect(transport:) to automatically send initialize request (#100)

* Update Client to automatically call initialize in connect

* Make Client.connect(transport:) return value discardable

* Fix example usage in README

* Update example code in transports to remove initialize call

* Deprecate initialize method

* Update tests

* Update README

* Fix sampling tests

* Fix race condition tests

Tests/MCPTests/HTTPClientTransportTests.swift

@@ -653,11 +653,8 @@ import Testing
                 }
             }
 
-            // Execute the complete flow
-            try await client.connect(transport: transport)
-
             // Step 1: Initialize client
-            let initResult = try await client.initialize()
+            let initResult = try await client.connect(transport: transport)
             #expect(initResult.protocolVersion == Version.latest)
             #expect(initResult.capabilities.tools != nil)