Improve the denoise quality from hard thresholding

[KedoKudo]

This PR introduces the following changes:

• patch in a block is now ordered based on similarity instead of the naive search order
• the missing threshold calculator is now added back in the hard thresholding function
• the example notebook is updated
• the second step, re-filtering is temporarily disabled as we need more time to understand how to properly compute the sigma for wiener_hadamard filter.

Example output from notebook (assuming 2% detector gain error):

Testing instructions

• Create and activate the conda environment
• Checkout the feature branch
• Run unit test
• Run the example notebook

EWM item: 5223

[jmborr]

I was able to run the notebook. Understanding the changes to the algorithms are currently above my pay grade 😊