add histogram visualization function

Create a function to plot the histogram of a volume based on seaborn.histplot, with an option to specify a particular slice for plotting.

qim3d/viz/explore.py

@@ -814,8 +814,8 @@ def histogram(
     """
 
     
-    if axis not in [0, 1, 2]:
-        raise ValueError("Axis must be 0, 1, or 2.")
+    if not (0 <= axis < vol.ndim):
+        raise ValueError(f"Axis must be an integer between 0 and {vol.ndim - 1}.")
     
     if isinstance(slice, int):
         if 0 <= slice < vol.shape[axis]: