Move mcp-spring-webflux and mcp-spring-webmvc to Spring AI 2.0 (#805)

The Spring-specific transport modules (mcp-spring-webflux,
mcp-spring-webmvc) have been moved out of the MCP Java SDK into the
Spring AI project (org.springframework.ai group), effective with
MCP Java SDK 1.0 and Spring AI 2.0. This is a breaking change.

- Delete mcp-spring-webflux and mcp-spring-webmvc source modules
- Remove both artifacts from mcp-bom and root pom.xml module list
- Update docs and README
- Add blog post explaining the breaking change with before/after
  migration examples

Resolves: #127

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

pom.xml

@@ -108,8 +108,6 @@
         <module>mcp-core</module>
         <module>mcp-json-jackson2</module>
         <module>mcp-json-jackson3</module>
-		<module>mcp-spring/mcp-spring-webflux</module>
-		<module>mcp-spring/mcp-spring-webmvc</module>
 		<module>mcp-test</module>
         <module>conformance-tests</module>
 	</modules>