Add deserialization support for 3D NDT maps.

[serraramiro1]

Proposed changes

Support loading 3D NDT maps from disk.

Type of change

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

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

The code used to generate the hdf5 file will be added in a separate PR, I've used a slightly modified version of this PR that got reverted:
#363