fix(tests): enable suppressTypeErrors on all integration tests

[rubiesonthesky]

PR Checklist

• [x] Addresses an existing open issue: fixes #1548
• [ ] That issue was marked as status: accepting prs
• [x] Steps in CONTRIBUTING.md were taken

Overview

After #1542

Enables suppressTypeErrors on all integration tests to track potential type errors on generated code.

Tests that add comments to files can't be used with it, so I had to add support for typestat.json files that define multiple steps. This is supported by the tool but it was not supported by integration test setup.