Rename new_ray to exceptional_ray

[paemurru]

When blowing up along a ray, the ray might coincide with an existing ray, so the variable name new_ray, as well as the corresponding function names, are unsuitable.

[codecov]

Codecov Report

Attention: Patch coverage is 96.15385% with 2 lines in your changes missing coverage. Please review.

Project coverage is 84.39%. Comparing base (8ab4265) to head (a97a673).
Report is 156 commits behind head on master.

Files with missing lines	Patch %	Lines
experimental/FTheoryTools/src/auxiliary.jl	50.00%	1 Missing ⚠️
...erimental/Schemes/src/ToricBlowups/constructors.jl	92.85%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4433      +/-   ##
==========================================
- Coverage   84.39%   84.39%   -0.01%     
==========================================
  Files         663      663              
  Lines       87954    87939      -15     
==========================================
- Hits        74227    74212      -15     
  Misses      13727    13727              

Files with missing lines	Coverage Δ
...xperimental/Schemes/src/ToricBlowups/attributes.jl	93.54% <100.00%> (ø)
experimental/Schemes/src/ToricBlowups/methods.jl	95.83% <100.00%> (ø)
experimental/Schemes/src/ToricBlowups/types.jl	72.72% <100.00%> (+0.41%)	⬆️
...alGeometry/PolyhedralFan/standard_constructions.jl	100.00% <100.00%> (ø)
experimental/FTheoryTools/src/auxiliary.jl	76.00% <50.00%> (ø)
...erimental/Schemes/src/ToricBlowups/constructors.jl	89.83% <92.85%> (ø)

... and 2 files with indirect coverage changes

[HereAround]

Looks like a good renaming. Thank you for working on this @paemurru !

[fingolfin]

@paemurru @HereAround I added the "topic: toric varieties" label. Please change this if you feel some other "topic" label is more appropriate.