Rudimentary NEST 3 adapter

[Helveg]

Describe the work done

• Added a NEST 3 based adapter for the creating of cells and synapses between them.

[codecov[bot]]

Codecov Report

Merging #699 (7c62f6d) into main (2305e0f) will increase coverage by 3.06%. Report is 7 commits behind head on main. The diff coverage is 82.24%.

:exclamation: Current head 7c62f6d differs from pull request most recent head c79d66c. Consider uploading reports for the commit c79d66c to get more accurate results

@@            Coverage Diff             @@
##             main     #699      +/-   ##
==========================================
+ Coverage   74.43%   77.49%   +3.06%     
==========================================
  Files         134      137       +3     
  Lines       15694    15344     -350     
==========================================
+ Hits        11682    11891     +209     
+ Misses       4012     3453     -559     

Files	Coverage Δ
bsb/config/__init__.py	88.05% <ø> (ø)
bsb/config/_attrs.py	94.82% <100.00%> (-0.15%)	:arrow_down:
bsb/config/_make.py	94.27% <100.00%> (+0.31%)	:arrow_up:
bsb/connectivity/detailed/voxel_intersection.py	86.53% <ø> (ø)
bsb/exceptions.py	100.00% <ø> (ø)
bsb/simulation/_backends.py	100.00% <100.00%> (ø)
bsb/simulation/adapter.py	86.36% <100.00%> (+10.17%)	:arrow_up:
bsb/simulation/cell.py	76.47% <100.00%> (+7.23%)	:arrow_up:
bsb/simulation/simulation.py	83.60% <100.00%> (+6.14%)	:arrow_up:
bsb/simulators/arbor/simulation.py	100.00% <100.00%> (ø)
... and 25 more

... and 20 files with indirect coverage changes

[Helveg]

@alessiomarta promemoriam: Merging this branch will break the NEURON devices, remind me to refactor them together with you once you have cleaned up your branch.