Add Layout.fixed: bool for a fast path in eq_row_in_page & row_type_visitor#2025

Centril merged 2 commits intomasterclockworklabs/SpacetimeDB:masterfrom

centril/speedup-eq_row_in_pageclockworklabs/SpacetimeDB:centril/speedup-eq_row_in_pageCopy head branch name to clipboard