Fix unused arg in SlidingPatchWSIDataset (Project-MONAI#6047)

### Description

This PR removes `map_level` from `SlidingPatchWSIDataset`, which seems
to be left from the previous changes and has not used anywhere. Also it
updates the outdated docstring.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [x] In-line docstrings updated.

---------

Signed-off-by: Behrooz <[email protected]>

monai/data/wsi_datasets.py

@@ -36,8 +36,8 @@ class PatchWSIDataset(Dataset):
 
     Args:
         data: the list of input samples including image, location, and label (see the note below for more details).
-        size: the size of patch to be extracted from the whole slide image.
-        level: the level at which the patches to be extracted (default to 0).
+        patch_size: the size of patch to be extracted from the whole slide image.
+        patch_level: the level at which the patches to be extracted (default to 0).
         transform: transforms to be executed on input data.
         include_label: whether to load and include labels in the output
         center_location: whether the input location information is the position of the center of the patch
@@ -171,26 +171,29 @@ def _transform(self, index: int):
 
 class SlidingPatchWSIDataset(Randomizable, PatchWSIDataset):
     """
-    This dataset extracts patches from whole slide images (without loading the whole image)
+    This dataset extracts patches in sliding-window manner from whole slide images (without loading the whole image).
     It also reads labels for each patch and provides each patch with its associated class labels.
 
     Args:
         data: the list of input samples including image, location, and label (see the note below for more details).
-        size: the size of patch to be extracted from the whole slide image.
-        level: the level at which the patches to be extracted (default to 0).
+        patch_size: the size of patch to be extracted from the whole slide image.
+        patch_level: the level at which the patches to be extracted (default to 0).
+        mask_level: the resolution level at which the mask/map is created (for `ProbMapProducer` for instance).
+        overlap: the amount of overlap of neighboring patches in each dimension (a value between 0.0 and 1.0).
+            If only one float number is given, it will be applied to all dimensions. Defaults to 0.0.
         offset: the offset of image to extract patches (the starting position of the upper left patch).
         offset_limits: if offset is set to "random", a tuple of integers defining the lower and upper limit of the
             random offset for all dimensions, or a tuple of tuples that defines the limits for each dimension.
-        overlap: the amount of overlap of neighboring patches in each dimension (a value between 0.0 and 1.0).
-            If only one float number is given, it will be applied to all dimensions. Defaults to 0.0.
         transform: transforms to be executed on input data.
+        include_label: whether to load and include labels in the output
+        center_location: whether the input location information is the position of the center of the patch
+        additional_meta_keys: the list of keys for items to be copied to the output metadata from the input data
         reader: the module to be used for loading whole slide imaging. Defaults to cuCIM. If `reader` is
 
             - a string, it defines the backend of `monai.data.WSIReader`.
             - a class (inherited from `BaseWSIReader`), it is initialized and set as wsi_reader,
             - an instance of a class inherited from `BaseWSIReader`, it is set as the wsi_reader.
 
-        map_level: the resolution level at which the output map is created.
         seed: random seed to randomly generate offsets. Defaults to 0.
         kwargs: additional arguments to pass to `WSIReader` or provided whole slide reader class
 
@@ -204,6 +207,7 @@ class SlidingPatchWSIDataset(Randomizable, PatchWSIDataset):
                 {"image": "path/to/image2.tiff", "patch_size": [20, 20], "patch_level": 2}
             ]
 
+        Unlike `MaskedPatchWSIDataset`, this dataset does not filter any patches.
     """
 
     def __init__(
@@ -220,7 +224,6 @@ def __init__(
         center_location: bool = False,
         additional_meta_keys: Sequence[str] = (ProbMapKeys.LOCATION, ProbMapKeys.SIZE, ProbMapKeys.COUNT),
         reader="cuCIM",
-        map_level: int = 0,
         seed: int = 0,
         **kwargs,
     ):
@@ -322,8 +325,8 @@ class MaskedPatchWSIDataset(PatchWSIDataset):
 
     Args:
         data: the list of input samples including image, location, and label (see the note below for more details).
-        size: the size of patch to be extracted from the whole slide image.
-        level: the level at which the patches to be extracted (default to 0).
+        patch_size: the size of patch to be extracted from the whole slide image.
+        patch_level: the level at which the patches to be extracted (default to 0).
         mask_level: the resolution level at which the mask is created.
         transform: transforms to be executed on input data.
         include_label: whether to load and include labels in the output