### What?
Fixes `select` handling for properties inside of unnamed tabs using the
mongodb adapter.
Additionally, refactors `traverseFields` in drizzle to reuse logic from
groups / collapsible or rows if unnamed.
### Why?
`select` must work for any fields.
### How?
Fixes the `'tab'` case in `buildProjectionFromSelect` to handle when the
field is an unnamed tab.
Adds extra tests for named tabs / unnamed.