Change NHS API to update with both systems' coordinates

[efaulhaber]

With this PR, I pass both system's coordinates to the NHS, together with the information which of the coordinates are changing and which are static. The NHS can then decide if and what to update.

For example, the grid NHS doesn't need to update for fluid-boundary NHS. A neighborhood search that explicitly computes the neighbor lists will have to update them because the fluid particles are moving.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 27.77778% with 13 lines in your changes are missing coverage. Please review.

Project coverage is 74.86%. Comparing base (ce24fd3) to head (f59c553).

❗ Current head f59c553 differs from pull request most recent head be5991a. Consider uploading reports for the commit be5991a to get more accurate results

Files	Patch %	Lines
src/grid_nhs.jl	33.33%	10 Missing ⚠️
src/trivial_nhs.jl	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main       #5      +/-   ##
==========================================
- Coverage   75.66%   74.86%   -0.80%     
==========================================
  Files           7        7              
  Lines         189      191       +2     
==========================================
  Hits          143      143              
- Misses         46       48       +2     

Flag	Coverage Δ
unit	74.86% <27.77%> (-0.80%)	⬇️

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[LasNikas]

LGTM!