Summary:
upgrade typeorm version, so Grist can run against newer versions of postgres.
Dusted off some old benchmarking code to verify that important queries don't get slower. They don't appear to, unlike for some intermediate versions of typeorm I tried in the past.
Most of the changes are because `findOne` changed how it interprets its arguments, and the value it returns when nothing is found. For the return value, I stuck with limiting its impact by emulating old behavior (returning undefined rather than null) rather than propagating the change out to parts of the code unrelated to the database.
Test Plan: existing tests pass; manual testing with postgres 10 and 14
Reviewers: georgegevoian
Reviewed By: georgegevoian
Differential Revision: https://phab.getgrist.com/D3613
Summary: This moves enough server material into core to run a home server. The data engine is not yet incorporated (though in manual testing it works when ported).
Test Plan: existing tests pass
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2552
