3.0: Guard again `archived` piece field

## To Reproduce
Add a field with name `archived` to a piece scheme and try to create new piece of this type.

## Expected behavior
Apostrophe should crash with a relevant message explaining this name is reserved.

## Describe the bug
Creating piece failed with app crash and long stack trace not hinting the problem.

## Details
OS/Browser: any

Reproduce the failure by adding an `archived` field to a piece scheme and creating a piece of that type. Trace the piece creation and field-validation entry points to find where reserved names are checked. Done means creation fails with a concise message explaining that `archived` is reserved, rather than an unhelpful stack trace.

Written by the indexing model from the issue text.