WIP: Adding seed to the random number generation to allow reproducibility

[kumaranu]

This PR is to put allow the user to provide random seed values to keep the results consistent while testing.

There are two instances of random number generation in the code:

1. geodesic_interpolate/interpolation.py
2. geodesic_interpolate/coord_utils.py

The goal here is to only provide the seed value when the user wants to.

[virtualzx-nad]

Thanks for adding reproducibility support! A few suggestions:

1. Consider using a single --seed parameter instead of two separate ones. The package can internally derive different seeds for different functions if needed.

2. The help text could be more concise, e.g.:

   ps.add_argument("--seed", type=int, help="Random seed for reproducible results")

3. The implementation part is missing - need to pass these seeds to the respective functions and set numpy's random seed.

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Review by Augment, approved by user.