docs(openapi): document GeoDatasets append params + add/enrich other core plugin endpoints

[tariqksoliman]

With Devin: JPL-Devin#106

Purpose

• A user reported that programmatically appending features to a GeoDataset (via the Configure API + long-term token) did not obey the group_id, start-time, and end-time fields that were set when the GeoDataset was created.
• Root cause is a documentation gap, not a code bug: the append endpoints only populate start_time/end_time/group_id/feature_id when the corresponding prop names are re-supplied on the append request. The *_field config stored at creation is read only to decide which columns exist, and is never used to compute per-feature values on append. Without the props, appended features get NULL for those columns and won't match temporal/group_id queries.
• This PR updates the Swagger/OpenAPI spec (docs/mmgis-openapi.json, served at /api-docs) and the GeoDatasets API markdown doc to document those params, then extends the audit to the rest of the core backend plugins — adding the remaining undocumented functional endpoints and enriching thin/undescribed field docs. No runtime code changed — docs only.

Proposed Changes

GeoDatasets (original scope)

• [ADD] POST /append/{name}: group_id_prop and feature_id_prop query params; documented body-level startProp/endProp/groupIdProp/featureIdProp; prominent note that append does not auto-reuse the fields configured at creation.
• [FIX] POST /append/{name} & /append/{name}/{start_end_prop}: request body IS the GeoJSON FeatureCollection, not a { geojson: ... } wrapper.
• [ADD] GET /get & /get/{layer}: group_id, id, spatialFilter, format. GET /aggregations: startProp, endProp, format. POST /search: operator, type, last. POST /recreate: groupIdProp, featureIdProp, filename + action description. Documented POST /intersect and GET /bulk_aggregations.
• Added E2E test tests/e2e/api/geodatasets-append-fields.spec.js covering create-with-fields → append-with-props → temporal + group_id queries, plus the append-without-props NULL gotcha.

Other core backend plugins (follow-up scope)

• [ADD] Previously-undocumented functional endpoints:
  • GET /api/stac/collections, GET /api/stac/collections/{collection}/export (new STAC tag)
  • POST /api/draw/aggregations
  • POST /api/utils/getminmax, POST /api/utils/ll2aerll_bulk
  • POST /api/configure/reference-mission/save-to-base
• [CHANGE] Enriched thin/undescribed field docs on existing endpoints: users login/signup/first_signup/resetPassword, utils getprofile/getbands, configure add/updateGeneralOptions, shortener shorten/expand, longtermtoken generate/clear.
  • Notably documented that longtermtoken period is milliseconds from creation (or the string never) — a unit string like "1d" parses to 1ms and the token is immediately expired.
• Excluded on request: Sightline endpoints, the internal testwebhooks stubs, and POST /api/configure/rename (empty no-op handler in code).