ENH: Pad or crop volume using `scil_volume_reshape.py`

[AntoineTheb]

Quick description

This new script allows to pad or crop a volume to a specified resolution (or to match a reference volume). It is complementary to scil_volume_resample.py.

This will be useful to build machine learning datasets where it is desirable to deal with fixed-size volumes.

Type of change

Check the relevant options.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Provide data, screenshots, command line to test (if relevant)

GDrive

fodf_128.nii.gz was used as the base file.

Checklist

• [X] My code follows the style guidelines of this project (run autopep8)
• [ ] I added relevant citations to scripts, modules and functions docstrings and descriptions
• [X] I have performed a self-review of my code
• [X] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [X] My changes generate no new warnings
• [X] I moved all functions from the script file (except the argparser and main) to scilpy modules
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 91.04478% with 6 lines in your changes missing coverage. Please review.

Project coverage is 68.84%. Comparing base (1d6f848) to head (7bae331). Report is 11 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1019 +/- ## ========================================== + Coverage 68.78% 68.84% +0.06% ========================================== Files 429 431 +2 Lines 22265 22332 +67 Branches 3324 3332 +8 ========================================== + Hits 15314 15375 +61 - Misses 5665 5670 +5 - Partials 1286 1287 +1 ``` | [Components](https://app.codecov.io/gh/scilus/scilpy/pull/1019/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | Coverage Δ | | |---|---|---| | [Scripts](https://app.codecov.io/gh/scilus/scilpy/pull/1019/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | `69.70% <85.36%> (+0.04%)` | :arrow_up: | | [Library](https://app.codecov.io/gh/scilus/scilpy/pull/1019/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | `67.63% <100.00%> (+0.09%)` | :arrow_up: |

[arnaudbore]

Quick discussion with @frheault, can you rename scil_volume_reshape_to_reference.py to scil_volume_reslice_to_reference.py ?

[AntoineTheb]

Good point @arnaudbore, done in 0e925ed

[AntoineTheb]

@arnaudbore ?

[AntoineTheb]

Really for merging @arnaudbore @frheault