Add a Pregnant field to the animal snapshot panels

[labkey-martyp]

Rationale

Adds a Pregnant field to the animal snapshot so staff can see at a glance whether a female is carrying an open conception, without opening the conception records to check.

A conception is open until a birth or a pregnancy outcome claims it, which no existing column expressed, so the field is backed by a new derived flag on the conception record. That flag is also useful on its own and is surfaced on the conceptions-by-dam report.

Related Pull Requests

None.

Changes

• Conception records carry a derived active flag marking the ones no birth or pregnancy outcome has claimed, and it appears on the conceptions-by-dam report alongside the outcome.
• The snapshot and Animal Details panels show a Pregnant field listing each open conception as a link to its record, or "No" when there are none.
• The dam's cached demographics are refreshed whenever a conception is entered, re-pointed or removed, and whenever a birth closes or reopens one. Previously only a pregnancy outcome refreshed her, so the field could show a stale value indefinitely.
• The outcome report no longer counts birth or pregnancy records whose status is explicitly non-public.
• Removed the Prev Id field from the snapshot panel.
• Test coverage for the field and the flag across the birth, conception and pregnancy flows.