Prepare well order modal for batch edit form

[IanLondon]

Overview

The existing Well Order field components need to be refactored so that it can be reused in the Batch Edit Transfer form, while continuing to be used in single-edit mode (in MixForm + SourceDestFields).

For the overall approach, see #7301, which we'll follow for all the modal fields.

Acceptance Criteria

When you open Well Order, it should start with the defaults (Order: Top to Bottom then Left to Right). It should not indicate mixed state, just use defaults for both fields if either of the 2 well order fields are in an indeterminate state.

Once the modal is open, it therefore won't indicate indeterminate or not, and will preserve the validation it does now (= no validation needed)