A planting can now choose one of its crop's alternate names (eg. "lauki"
for calabash, "aubergine" for eggplant) and shows it instead of the
crop's primary name.
- plantings.alternate_name_id, validated to belong to the planting's crop
- Planting#display_name, used on cards, the planting page, garden lists,
the member page, the homepage and the RSS/ICS feeds
- planting form offers the crop's alternate names, preselecting the one
that was searched for
- crop autosuggest shows the matched alternate name, eg.
"aubergine (eggplant)", via matched_alternate_name in the search JSON
Part of #554
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>