[ODSC-75899] : Add post-processing step for forecast clipping

[codeloop]

Add post-processing step for forecast clipping

This change introduces a new post-processing step for the forecast operator that allows users to clip the forecast output to a specified minimum and maximum value. This is useful for ensuring that the forecast values remain within a realistic or desirable range.

This change includes:

• A new PostprocessingSteps configuration to define the min/max clipping values.
• Updates to the operator schema to expose the new configuration.
• Implementation of the clipping logic using numpy.clip.
• A new test case to verify the clipping functionality.