Allow server autors to set CacheScope for tools/list and server/discover

[abdulkareemnalband]

Pre-submission Checklist

• I have verified this would not be more appropriate as a feature request in a specific repository
• I have searched existing discussions to avoid duplicates

Your Idea

Allow configuring CacheScope and ttl in AddMcpServer and WithToolsFromAssembly

Scope

• Protocol Specification
• SDK Features
• Documentation
• Developer Experience
• Other