Phase 4: order and shapes, the rules a pack can choose, and the output model #754

Part of #747. Mostly independent of phases 2 and 3.

Order versus shape (decided): a language supplies only a default order. The shapes each order accepts (where titles, suffixes, particles and commas sit) belong to that order, in the core.

The work:

• An inventory of the shapes each order accepts, extending tools/differential/shapes.py (Should docs/ document input shapes for the family-first name orders, and does a trailing particle belong in the notation? #469's inventory).
• The rules a pack can choose and parameterize in its TOML ([rules], ending rules such as -ovich), with implementations in the core.
• The output model: align with CLDR's fields, add surname2, a patronymic or neutral parent-names field (a matronymic fits it too), family allowed to be empty, an alternate or reading view, and what middle means.

Related questions are linked here as sub-issues.