(core) upgrade typeorm so we can support newer postgres

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

app/gen-server/entity/AclRule.ts

@@ -54,5 +54,5 @@ export class AclRuleDoc extends AclRule {
   public document: Document;
 
   @RelationId((aclRule: AclRuleDoc) => aclRule.document)
-  public docId: number;
+  public docId: string;
 }