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

Sources/MCP/Base/Transports/HTTPClientTransport.swift

@@ -41,9 +41,6 @@ import Logging
 /// let client = Client(name: "MyApp", version: "1.0.0")
 /// try await client.connect(transport: transport)
 ///
-/// // Initialize the connection
-/// let result = try await client.initialize()
-///
 /// // The transport will automatically handle SSE events
 /// // and deliver them through the client's notification handlers
 /// ```

Sources/MCP/Base/Transports/NetworkTransport.swift

@@ -51,9 +51,6 @@ import Logging
     /// // Use the transport with an MCP client
     /// let client = Client(name: "MyApp", version: "1.0.0")
     /// try await client.connect(transport: transport)
-    ///
-    /// // Initialize the connection
-    /// let result = try await client.initialize()
     /// ```
     public actor NetworkTransport: Transport {
         /// Represents a heartbeat message for connection health monitoring.

Sources/MCP/Base/Transports/StdioTransport.swift

@@ -44,9 +44,6 @@ import struct Foundation.Data
     /// // Create a transport and connect
     /// let transport = StdioTransport()
     /// try await client.connect(transport: transport)
-    ///
-    /// // Initialize the connection
-    /// let result = try await client.initialize()
     /// ```
     public actor StdioTransport: Transport {
         private let input: FileDescriptor