Redefine Cone and Torus: φ::Tuple{T,T} => φ::T

[fhagemann]

This PR changes the definition of the polar angle φ for both Cone and Torus as requested in #215 and #236.
φ is can now only be full 2π (Nothing) or a number (T), where φ = 50° describes the range from 0° to 50°.
This is explicitly required in the source code by demanding φ::TP where {TP <: Union{Nothing,T}}.

I also added tests for Cone and Torus which should cover most (if not all) of the cases that we describe and increase the code coverage. I also spotted some bugs while running the tests that are fixed with this PR.

I tried out some combinations of rotations and translations, and the implementation seems to be right
(basically, we set φ to be the width of the former φ interval and add a rotation around the Z axis by φ[1]).

Full 2π Cone

cone:
  r:
    bottom:
      from: 1.0
      to: 2.0
    top:
      from: 1.0
      to: 2.0
  h: 2.0
  rotation:
    X: 45.0°
  origin: [0,1,0]

Partial Cone

cone:
  r:
    bottom:
      from: 1.0
      to: 2.0
    top:
      from: 1.0
      to: 2.0
  phi:
    from: 80.0°
    to: 140.0°
  h: 2.0
  rotation:
    X: 45.0°
  origin: [0,1,0]

The tricky part is when intervals need to be converted to the new φ syntax, e.g. when determining the EllipticalSurfaces that describe φ cross-sections of a Torus.

Then θ::Tuple{T,T} is converted to the "new" φ::T through φ = abs(-(θ...)) and a rotation around θ[1]:

Another nice thing is that the bulletized point contacts from SigGen configuration files now look quite decent, as they are not constructed using CSGDifference anymore:

sim = Simulation(SSD_examples[:SigGen])
plot(
    plot(sim.detector, st = :mesh3d)
    plot(sim.detector.contacts[1], st = :mesh3d)
)