refs https://github.com/TryGhost/Ghost/issues/10318
`Settings.populateDefaults()` is run before migrations during Ghost's startup. This can cause problems when new settings table columns are added (and populated in `default-settings.json`) because `populateDefaults()` was using the model layer which assumes that those columns are available, resulting in `ER_BAD_FIELD_ERROR: Unknown column` type errors.
- query the database for the available `settings` table columns
- switch to using raw knex queries without Bookshelf for insertions so that we're in control of the columns that are added
- use `_.pick` to skip any properties in `default-settings.json` that do not match to an available column - those columns will be added and populated by later migrations
- moving away from using the model to insert settings has the side-effect of not emitting `settings.added/edited` and `settings.x.added/edited` events, this should be fine because `populateDefaults()` is called before anything else is set up and listening
- added a call to `populateDefaults()` in our knex-migrator "before migration" hook so that we have consistent db state across both startup initialised migrations and manually triggered knex migrations
f45198245f