Deduplicate basic_json internals; make insert(pos, json&&) move - #5727

Deduplicate basic_json internals; make insert(pos, json&&) move#5727

nlohmann merged 16 commits into

developnlohmann/json:developfrom

techdebt/5724-core-cleanupnlohmann/json:techdebt/5724-core-cleanupCopy head branch name to clipboard