MCP Server: Replace the cpg_llm_analyze tool with a suggest_concepts MCP prompt.

[lshala]

Extracted from #2574 to make the PR easier to review.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.17%. Comparing base (db6b637) to head (a864fa8).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

Files with missing lines	Coverage Δ
...de/fraunhofer/aisec/cpg/mcp/mcpserver/McpServer.kt	100.00% <100.00%> (ø)
...pg/mcp/mcpserver/tools/CpgSuggestConceptsPrompt.kt	100.00% <100.00%> (ø)
...er/aisec/cpg/mcp/mcpserver/tools/utils/Payloads.kt	48.93% <ø> (-1.07%)	⬇️

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.