feat(types): add SEP-2549 cache hints to result models

[MicroYui]

Summary

Implements SEP-2549 cache hints for Python SDK protocol result models.

Adds ttlMs and cacheScope support to:

• ListToolsResult
• ListPromptsResult
• ListResourcesResult
• ListResourceTemplatesResult
• ReadResourceResult

The SDK defaults to ttlMs=0 and cacheScope="public" so existing Python code constructing these models remains usable while serialized responses include the new cache hint fields. Older server responses that omit the fields also parse with those defaults.

This PR does not implement client-side caching, cache invalidation logic, or new high-level MCPServer cache configuration APIs.

Fixes#2802.

Tests

• uv run --frozen pytest tests/test_types.py -q
• uv run --frozen pytest tests/server/lowlevel/test_server_listing.py tests/interaction/lowlevel/test_wire.py tests/server/mcpserver/test_server.py -q
• uv run --frozen pytest tests/interaction/test_coverage.py tests/interaction/lowlevel/test_wire.py -q
• uv run --frozen ruff format --check .
• uv run --frozen ruff check .
• uv run --frozen pyright --pythonplatform Linux

[maxisbey]

Thanks for the PR. This has since landed via #2849. I'm closing this out as part of a backlog cleanup now that v2 is out. Feel free to reopen if this is still relevant.

_{AI Disclaimer}