Clean the CNS part of the rigidbody docking module

[amjjbonvin]

• Updated scripts to the latest 2.4 version
• Removed unnecessary parts (current implementation only supports distance restraints)
• Corrected missing parameters
• Made random removal and generation of seed files work
• Added model number in the generated CNS scripts encoded in $count
• The docking scenario now shows a proper behaviour of the generated models

Still todo for completeness:

• Add proper support for unambiguous and hbond restraints

[codecov-commenter]

Codecov Report

Merging #124 (b5966bf) into main (5eb034b) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #124      +/-   ##
==========================================
- Coverage   43.43%   43.41%   -0.03%     
==========================================
  Files          38       38              
  Lines        1874     1875       +1     
==========================================
  Hits          814      814              
- Misses       1060     1061       +1     

Impacted Files	Coverage Δ
src/haddock/libs/libcns.py	14.45% <0.00%> (ø)
src/haddock/modules/sampling/rigidbody/__init__.py	22.07% <0.00%> (-0.30%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5eb034b...b5966bf. Read the comment docs.

[rvhonorato]

Tested and working fine, thanks for the edits @amjjbonvin!

This closes #123 by refactoring the CNS part