Re-added old types for backwards compatibility (#158)

Author: dstibbe

kotlin-sdk-core/api/kotlin-sdk-core.api

@@ -450,9 +450,8 @@ public final class io/modelcontextprotocol/kotlin/sdk/CompleteResult$Completion$
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
-public abstract interface class io/modelcontextprotocol/kotlin/sdk/ContentBlock {
+public abstract interface class io/modelcontextprotocol/kotlin/sdk/ContentBlock : io/modelcontextprotocol/kotlin/sdk/PromptMessageContent {
 	public static final field Companion Lio/modelcontextprotocol/kotlin/sdk/ContentBlock$Companion;
-	public abstract fun getType ()Ljava/lang/String;
 }
 
 public final class io/modelcontextprotocol/kotlin/sdk/ContentBlock$Companion {
@@ -2039,20 +2038,10 @@ public final class io/modelcontextprotocol/kotlin/sdk/PromptMessage$Companion {
 }
 
 public abstract interface class io/modelcontextprotocol/kotlin/sdk/PromptMessageContent {
-	public static final field Companion Lio/modelcontextprotocol/kotlin/sdk/PromptMessageContent$Companion;
 	public abstract fun getType ()Ljava/lang/String;
 }
 
-public final class io/modelcontextprotocol/kotlin/sdk/PromptMessageContent$Companion {
-	public final fun serializer ()Lkotlinx/serialization/KSerializer;
-}
-
 public abstract interface class io/modelcontextprotocol/kotlin/sdk/PromptMessageContentMultimodal : io/modelcontextprotocol/kotlin/sdk/PromptMessageContent {
-	public static final field Companion Lio/modelcontextprotocol/kotlin/sdk/PromptMessageContentMultimodal$Companion;
-}
-
-public final class io/modelcontextprotocol/kotlin/sdk/PromptMessageContentMultimodal$Companion {
-	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
 public final class io/modelcontextprotocol/kotlin/sdk/PromptReference : io/modelcontextprotocol/kotlin/sdk/Reference {

kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types.kt

@@ -970,13 +970,22 @@ public data class GetPromptRequest(
     override val method: Method = Method.Defined.PromptsGet
 }
 
+@Deprecated("For backwards compatibility; use ContentBlock instead", ReplaceWith("ContentBlock"))
+public sealed interface PromptMessageContent {
+    public val type: String
+}
+
+@Deprecated(
+    "For backwards compatibility; use CreateMessageResultContent or SamplingMessageContent instead",
+    ReplaceWith("CreateMessageResultContent"),
+)
+public sealed interface PromptMessageContentMultimodal : PromptMessageContent
+
 /**
  * Represents the types of a ContentBlock
  */
 @Serializable(with = ContentBlockPolymorphicSerializer::class)
-public sealed interface ContentBlock {
-    public val type: String
-}
+public sealed interface ContentBlock : PromptMessageContent
 
 /**
  * Represents content for the CreateMessageResult