Improve Benchmarking of retrieval_core and graph_analytics

Increase `retrieval_core` and `graph_analytics` benchmark sizes to produce stable timings

Search the repository for the `retrieval_core` and `graph_analytics` benchmark definitions and start by running their current benchmarks to establish a baseline. Increase their benchmark sizes and rerun them; the work is done when both produce stable, representative timings without changing the algorithms.

Written by the indexing model from the issue text.