feat(api): expose import row diagnostics (#1644)

* feat(api): expose import row diagnostics

* fix(api): stabilize import row diagnostics

* fix(api): harden import row diagnostics

* fix(api): number Mint import diagnostics rows

* fix(api): enforce unique import row diagnostics

* fix(api): address import row diagnostics review

test/models/mint_import_test.rb

@@ -0,0 +1,19 @@
+require "test_helper"
+
+class MintImportTest < ActiveSupport::TestCase
+  setup do
+    @family = families(:dylan_family)
+  end
+
+  test "generated rows preserve stable source row numbers" do
+    import = @family.imports.create!(
+      type: "MintImport",
+      raw_file_str: file_fixture("imports/mint.csv").read,
+      col_sep: ","
+    )
+
+    import.generate_rows_from_csv
+
+    assert_equal (1..10).to_a, import.rows.order(:source_row_number).pluck(:source_row_number)
+  end
+end