featire: Ensure img_path is of type Path

Closes #106

Ensures that if fileversion >= 0.2 is being loaded that the `data["img_path"]` variable is of type `Path`.

Adds to the test suite a 0.2 sample file to check this (and expands on the keys of the dictionary).

AFMReader/topostats.py

@@ -41,7 +41,8 @@ def load_topostats(file_path: Path | str) -> tuple:
     try:
         with h5py.File(file_path, "r") as f:
             data = unpack_hdf5(open_hdf5_file=f, group_path="/")
-
+            if data["topostats_file_version"] >= 0.2:
+                data["img_path"] = Path(data["img_path"])
             file_version = data["topostats_file_version"]
             logger.info(f"[{filename}] TopoStats file version : {file_version}")
             image = data["image"]

tests/test_topostats.py

@@ -19,9 +19,36 @@
             0.1,
             (64, 64),
             1.97601171875,
-            {"topostats_file_version", "image", "pixel_to_nm_scaling"},
+            {
+                "pixel_to_nm_scaling",
+                "image",
+                "topostats_file_version",
+            },
             112069.51332503435,
-            id="version",
+            id="version 0.1",
+        ),
+        pytest.param(
+            "sample_0_2.topostats",
+            0.2,
+            (64, 64),
+            1.97601171875,
+            {
+                "disordered_traces",
+                "filename",
+                "grain_curvature_stats",
+                "grain_masks",
+                "height_profiles",
+                "image",
+                "image_original",
+                "img_path",
+                "nodestats",
+                "ordered_traces",
+                "pixel_to_nm_scaling",
+                "splining",
+                "topostats_file_version",
+            },
+            1176.601500471239,
+            id="version 0.2",
         ),
     ],
 )
@@ -47,3 +74,5 @@ def test_load_topostats(
     assert set(result_data.keys()) == data_keys  # type: ignore
     assert result_data["topostats_file_version"] == topostats_file_version
     assert result_image.sum() == image_sum
+    if topostats_file_version >= 0.2:
+        assert isinstance(result_data["img_path"], Path)