Refactor of json + json schema validation api. Moved classes rom mcp-json to mcp-core making mcp-json unnecessary

[scottslewis]

into mcp-core.

Moved classes from mcp-json jar into new packages io.modelcontextprotocol.json, io.modelcontextprotocol.json.schema, and io.modelcontextprotocol.json.internal. Updated dependencies on moved classes in mcp-core, mcp-jackson2 and other maven modules.

Motivation and Context

This provides a fix for #612 and removed mcp-core dependencies on mcp-json. After these refactoring, mcp-json project/jar is not needed and only mcp-core and mcp-jackson2 have to be deployed to have a functioning sdk.

How Has This Been Tested?

Have run test suite locally. Some of the mcp-core tests are failing...apparently because of the environment setup for docker...for example:

[ERROR] HttpSseMcpAsyncClientLostConnectionTests.testPingWithExactExceptionType ┬╗ ExceptionInInitializer
[ERROR] HttpSseMcpAsyncClientTests.startContainer:41 ┬╗ IllegalState Previous attempts to find a Docker environment failed. Will not retry. Please see logs and check configuration

Breaking Changes

As per #612, previously mcp-core had compile-time dependencies on mcp-json, meaning that mcp-core, mcp-json, and mcp-jackson2 had to be deployed together or nothing would work...even code that just used mcp-core.

Types of changes

• [ X] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• [X ] Breaking change (fix or feature that would cause existing functionality to change)
• [ X] Documentation update

Checklist

• [X ] I have read the MCP Documentation
• [X ] My code follows the repository's style guidelines
• [X ] New and existing tests pass locally
• [X ] I have added appropriate error handling
• [ X] I have added or updated documentation as needed