move name validation in production to separate validation step

[yaacovCR]

Motivation:

• Improve known-valid schema construction time as much as possible.

Background:

• All schema validation except name validation is currently performed separately in the validateSchema(...), which optimizes schema construction for known-valid schemas.
• Name validation is an exception, which provides useful localized dev feedback if a naming mistake has been made, see #4362 and especially this comment which details some history of the code changes.
• This PR adds name validation to the validateSchema(...) step and makes it so that in a production environment only, name validation is skipped during schema construction.

Depends on:

• #4426

Prior proposals:

• #4423
• #4427