update_competitor_benchmark

Replace the project's Competitor Benchmark grid: competitors as rows, features as columns, and for each competitor the ids of the features it has. This replaces the whole grid, the same way editing the table in the wizard does, so include everything you want kept (get_project returns the current grid as competitorBenchmark). Ids are any unique strings you choose, e.g. "f1" / "c1"; keep existing ids when editing. Reference data only: it never changes the feasibility numbers.