Fix a bug with sqllite default values and inserts

[jondlm]

I found a bug where sequelize was incorrectly inserting a raw string when it should have been respecting the default defined at the database column level. This PR fixes it by reducing the fields that sequelize inserts to to only those defined on the values.

Here's a repro. Make a table like this:

CREATE TABLE accounts (
  "id"                  TEXT PRIMARY KEY,
  "name"                TEXT NOT NULL,
  "created"             TEXT DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ')),
) WITHOUT ROWID;

And try to insert just a record with just a "name". You'll end up with the literal strftime('%Y-%m-%dT%H:%M:%SZ') for the created column.

[bradleyboy]

Way late but thanks for this 🙏