introduce new mu map dataset consisting of patches

mu_map/data/patch_dataset.py

+from mu_map.data.datasets import MuMapDataset
+
+class MuMapPatchDataset(MuMapDataset):
+
+    def __init__(self, dataset_dir, patches_per_image=100, patch_size=32):
+        super().__init__(dataset_dir)
+
+        self.patches_per_image=patches_per_image
+        self.patch_size=patch_size
+
+    def __getitem___(self, index:int):
+        return super()[index]
+
+    def __len__(self):
+        return super().__len__() * self.patches_per_image
+
+
+if __name__ == "__main__":
+    dataset = MuMapPatchDataset("data/initial/")
+
+    print(f"Images {len(dataset)}")