feat(mcp): Update to MCP SDK 0.8.0-SNAPSHOT and fix client initialization

- Make MCP client initialization blocking with .block() call
- Upgrade MCP SDK version from 0.7.0 to 0.8.0-SNAPSHOT

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

auto-configurations/spring-ai-mcp-client/src/main/java/org/springframework/ai/autoconfigure/mcp/client/McpClientAutoConfiguration.java

@@ -268,7 +268,7 @@ public class McpClientAutoConfiguration {
 				var syncClient = syncSpec.build();
 
 				if (commonProperties.isInitialized()) {
-					syncClient.initialize();
+					syncClient.initialize().block();
 				}
 
 				mcpSyncClients.add(syncClient);

mcp/common/src/main/java/org/springframework/ai/mcp/McpToolUtils.java

@@ -142,8 +142,9 @@ public final class McpToolUtils {
 			try {
 				String callResult = toolCallback.call(ModelOptionsUtils.toJsonString(request));
 				if (mimeType != null && mimeType.toString().startsWith("image")) {
-					return new McpSchema.CallToolResult(List.of(new McpSchema.ImageContent(List.of(Role.ASSISTANT),
-							null, "image", callResult, mimeType.toString())), false);
+					return new McpSchema.CallToolResult(List
+						.of(new McpSchema.ImageContent(List.of(Role.ASSISTANT), null, callResult, mimeType.toString())),
+							false);
 				}
 				return new McpSchema.CallToolResult(List.of(new McpSchema.TextContent(callResult)), false);
 			}

pom.xml

@@ -239,7 +239,7 @@
 		<okhttp3.version>4.12.0</okhttp3.version>
 
 		<!-- MCP-->
-		<mcp.sdk.version>0.7.0</mcp.sdk.version>
+		<mcp.sdk.version>0.8.0-SNAPSHOT</mcp.sdk.version>
 
 		<!-- plugin versions -->
 		<antlr.version>4.13.1</antlr.version>