Fix event stream line parsing to handle CRLF and empty lines correctly (#89)

* Optimized code in `connectToEventStream` to use `.lines` computed value of `AsyncSequence` to produce a `AsyncLineSequence` instead of building a lines manually.

* - Reverter use of `lines` (it swallows newlines)
- Fiexed original issue I experienced with line 229 `while let newlineIndex = buffer.firstIndex(of: "\n") {` not handling "\r\n" properly
- Added unit test to test for "\r\n" scenario
- Simplified `end of event` test - `line` creation trims newline, added code trims carriage return. Only thing that should be left is an empty line

Sources/MCP/Base/Transports/HTTPClientTransport.swift

@@ -226,12 +226,16 @@ public actor HTTPClientTransport: Actor, Transport {
                 buffer.append(char)
 
                 // Process complete lines
-                while let newlineIndex = buffer.firstIndex(of: "\n") {
-                    let line = buffer[..<newlineIndex]
+                while let newlineIndex = buffer.utf8.firstIndex(where: { $0 == 10 }) {
+                    var line = buffer[..<newlineIndex]
+                    if line.hasSuffix("\r") {
+                        line = line.dropLast()
+                    }
+
                     buffer = String(buffer[buffer.index(after: newlineIndex)...])
 
                     // Empty line marks the end of an event
-                    if line.isEmpty || line == "\r" || line == "\n" || line == "\r\n" {
+                    if line.isEmpty {
                         if !eventData.isEmpty {
                             // Process the event
                             if eventType == "id" {
@@ -256,6 +260,10 @@ public actor HTTPClientTransport: Actor, Transport {
                         continue
                     }
 
+                    if line.hasSuffix("\r") {
+                        line = line.dropLast()
+                    }
+                    
                     // Lines starting with ":" are comments
                     if line.hasPrefix(":") { continue }