Improve spatial_hash function to avoid spatial periodicity in the hash function

[glpuga]

Proposed changes

Adds two commits:

• The first one adds periodicity checks that the existing hash function does not pass.
• The second one updates the hash function to pass old and new tests.

Based on:

• https://en.wikipedia.org/wiki/Hash_function#Fibonacci_hashing
• https://probablydance.com/2018/06/16/fibonacci-hashing-the-optimization-that-the-world-forgot-or-a-better-alternative-to-integer-modulo/

Type of change

• 🐛 Bugfix (change which fixes an issue)
• 🚀 Feature (change which adds functionality)
• 📚 Documentation (change which fixes or extends documentation)

💥 Breaking change! Explain why a non-backwards compatible change is necessary or remove this line entirely if not applicable.

Checklist

Put an x in the boxes that apply. This is simply a reminder of what we will require before merging your code.

• Lint and unit tests (if any) pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• All commits have been signed for DCO

Additional comments

Anything worth mentioning to the reviewers.

[nahueespinosa]

@glpuga This is super interesting! What's the motivation behind this? Is this an improvement to better support 3D (6-DOF) or is it something else?

[glpuga]

What's the motivation behind this? Is this an improvement to better support 3D (6-DOF) or is it something else?

This is related to #275 , since I'm reusing this for that estimator. While I don't need more than three dimensions there, I noticed the periodicity in the hash when looking at the code. I don't think we should ignore the information in the upper bits of each dimension, it's better to blend it all together by spreading information in all the space.

[nahueespinosa]

LGTM!