PDB partial charges & CMake NumPy detection

[godotalgorithm]

This PR resolves #161 by printing partial charges to PDB output when the PRTCHAR keyword is specified, and resolves #162 by adding a more verbose error message when CMake detects Python without NumPy that includes suggestions for how to resolve the problem.

Status

• [x] Ready for merge

[codecov[bot]]

Codecov Report

Merging #171 (430d091) into main (206107f) will decrease coverage by 0.01%. The diff coverage is 71.42%.

@@            Coverage Diff             @@
##             main     #171      +/-   ##
==========================================
- Coverage   66.89%   66.89%   -0.01%     
==========================================
  Files         331      331              
  Lines       73890    73894       +4     
==========================================
+ Hits        49428    49430       +2     
- Misses      24462    24464       +2     

Files Changed	Coverage Δ
src/output/pdbout.F90	88.60% <66.66%> (-0.33%)	:arrow_down:
src/input/wrtkey.F90	64.58% <100.00%> (ø)