add tests for NaturalIndex in SpatialTreeInterface tests

this probably isn't the best test suite but at least there is something..

Author: asinghvi17

test/utils/SpatialTreeInterface.jl

@@ -4,6 +4,7 @@ using GeometryOps.SpatialTreeInterface
 using GeometryOps.SpatialTreeInterface: isspatialtree, isleaf, getchild, nchild, child_indices_extents, node_extent
 using GeometryOps.SpatialTreeInterface: query, depth_first_search, dual_depth_first_search
 using GeometryOps.SpatialTreeInterface: FlatNoTree
+using GeometryOps.NaturalIndexing: NaturalIndex
 using Extents
 using GeoInterface: GeoInterface as GI
 using SortTileRecursiveTree: STRtree
@@ -200,6 +201,14 @@ end
         test_geometry_support(TreeType)
         test_find_point_in_all_countries(TreeType)
     end
+# Test NaturalIndex implementation
+@testset "NaturalIndex" begin
+    test_basic_interface(NaturalIndex)
+    test_child_indices_extents(NaturalIndex)
+    test_query_functionality(NaturalIndex)
+    test_dual_query_functionality(NaturalIndex)
+    test_geometry_support(NaturalIndex)
+    # test_find_point_in_all_countries(NaturalIndex)
 end