fix(lagoon): keep Status plugin-only; migrate:status adds the framework sets itself (WR-12)

57a849d made lagoon.Status read migrationSets, which changed its result
for consumers: the framework sets came first and a plugin with no
migrations lost its row. Status is back to its pre-57a849d behaviour.
migrate:status (table and --json) now reads the unexported setStatus,
which lists the framework sets and the plugins from migrationSets, so it
still agrees with migrate --pretend. Both share historyRows.

- TestStatusPluginRows pins Status: plugin rows only, an empty row for a
  plugin with no migrations or no history table, none without HasMigrations
- TestMigrateStatusJSON also checks the table lists the framework sets
- TestTwoPluginMigrationSetsIsolated and TestDocsMigrate are back to the
  plugin-only rows

scripts/check-phase19.8.sh

@@ -201,6 +201,8 @@ DOCKER_LAGOON_TESTS=(
 	TestMigrateAppliedLines
 	# quick 261022-4z8 (re-review fixes): WR-13.
 	TestMigrateRereadFailureWarns
+	# quick 261022-4z8: WR-12 rework, lagoon.Status stays plugin-only.
+	TestStatusPluginRows
 )
 DOCKER_CABANA_TESTS=(TestTokenCreateJSON TestTokenListJSON TestTokenCreateQuietKeepsToken)