Adding CTF method to PaganinProcessor

[deding2000]

Description

Modifying the PaganinProcessor by adding the Contrast Transfer Function (CTF) approach as an alternative to Paganin to do phase retreival (see e.g https://opg.optica.org/oe/fulltext.cfm?uri=oe-26-9-11110). Fixes issue #2265

Example Usage

processor = PaganinProcessor(delta=1e-7,beta=1e-9,filter_type="ctf_method")
processor.set_input(data)
phased_image = processor.get_output()

Contribution Notes

• The content of this Pull Request (the Contribution) is intentionally submitted for inclusion in CIL (the Work) under the terms and conditions of the Apache-2.0 License
• I confirm that the contribution does not violate any intellectual property rights of third parties

❤️ Thanks for your contribution!

[gfardell]

Thank you, this will be a great addition.