Migrate project to Multiplatform (KMP) (#22)

* Migrate to Kotlin multiplatform

* Fix publication

* Switch to using `alias` for the AtomicFu plugin

---------

Co-authored-by: Alexander Sysoev <Alexander.Sysoev@jetbrains.com>

src/test/kotlin/InMemoryTransport.kt

@@ -1,54 +0,0 @@
-import io.modelcontextprotocol.kotlin.sdk.JSONRPCMessage
-import io.modelcontextprotocol.kotlin.sdk.shared.Transport
-
-/**
- * In-memory transport for creating clients and servers that talk to each other within the same process.
- */
-class InMemoryTransport : Transport {
-    private var otherTransport: InMemoryTransport? = null
-    private val messageQueue: MutableList<JSONRPCMessage> = mutableListOf()
-
-    override var onClose: (() -> Unit)? = null
-    override var onError: ((Throwable) -> Unit)? = null
-    override var onMessage: (suspend ((JSONRPCMessage) -> Unit))? = null
-
-    /**
-     * Creates a pair of linked in-memory transports that can communicate with each other.
-     * One should be passed to a Client and one to a Server.
-     */
-    companion object {
-        fun createLinkedPair(): Pair<InMemoryTransport, InMemoryTransport> {
-            val clientTransport = InMemoryTransport()
-            val serverTransport = InMemoryTransport()
-            clientTransport.otherTransport = serverTransport
-            serverTransport.otherTransport = clientTransport
-            return Pair(clientTransport, serverTransport)
-        }
-    }
-
-    override suspend fun start() {
-        // Process any messages that were queued before start was called
-        while (messageQueue.isNotEmpty()) {
-            messageQueue.removeFirstOrNull()?.let { message ->
-                onMessage?.invoke(message) // todo?
-            }
-        }
-    }
-
-    override suspend fun close() {
-        val other = otherTransport
-        otherTransport = null
-        other?.close()
-        onClose?.invoke()
-    }
-
-    override suspend fun send(message: JSONRPCMessage) {
-        val other = otherTransport ?: throw IllegalStateException("Not connected")
-
-        if (other.onMessage != null) {
-            other.onMessage?.invoke(message) // todo?
-        } else {
-            other.messageQueue.add(message)
-        }
-    }
-}