Clean up schema for table lfs_objects
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From https://gitlab.com/gitlab-com/infrastructure/issues/1709 (private to GitLab employees):
- [x] Wrong data type: created_at should be timestamptz
- [x] Wrong data type: updated_at should be timestamptz
- [ ] Missing constraint: created_at NOT NULL
- [ ] Missing constraint: updated_at NOT NULL
- [ ] Missing constraint: file NOT NULL
- [ ] Wrong data type: oid should be bytea - save 70 MB
- [ ] Wrong data type: file should be bytea - save 70 MB
- [ ] Name change: "oid" is used in PG catalogs, recommend changing to another name
- [ ] Duplicate data: Could 'id' be used instead of 'oid', removing the need for oid entirely? (save 92MB)
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