Crop edges update simplified

[jordiferrero]

Description of the change

Following the request to make #142 cleaner and separate the crop_ede function from other changes, this is the clean version of the PR, aiming to extend the functionality of crop_edges.

Progress of the PR

• [x] Change implemented (can be split into several points),
• [x] docstring updated (if appropriate),
• [x] update user guide (if appropriate),
• [x] added tests,
• [x] added line to CHANGELOG.md,
• [x] ready for review.