Simplify spherical quick_index and kde reconstruction

[clevelam]

Background

• The previous spherical implementation used for KDE was error prone and required some pretty complex logic from x,y-r,theta mapping. This PR simplifies the approach by translating all locations in the quick index into r,theta space. Additionally the coarse grid data stride is then stored in r,theta as well making it much simpler to do the data mapping. It only required a few motifications in spherical geometry (primarly to catch the possibility of overlapping boundaries at the theta=0,2Pi interface).

Purpose of Pull Request

• Simplify spherical mapping for KDE by moving the mapping directly to the quick _index class
• Fixes re-git issue #1358

Description of changes

• quick_index now translates (x,y) or (r,z) coordinates into spherical (r,theta) coordinates directly
• KDE only has a small dependency on the spherical quick index implementation (used for error checking)
• KDE no-longer need special mapping from x,y->r,theta.
• This allowed spherical and cartesian coordinates to share the KDE boundary condition treatments and other mapping functions.

Status

• Reference:
  • Pre-Merge Code Review
  • CDash Status
• Checks
  • [x] Travis/Appveyor CI checks pass
  • [x] Code coverage does not decrease
  • [x] Valgrind test passes
  • [x] Toss3 checks pass
  • [x] Trinitite checks pass
  • [x] Code reviewed/approved, sufficient DbC checks, testing, documentation

[codecov[bot]]

Codecov Report

Merging #1123 (b41b77c) into develop (fc46b6d) will increase coverage by 0.0%. The diff coverage is 96.6%.

@@           Coverage Diff            @@
##           develop   #1123    +/-   ##
========================================
  Coverage     89.0%   89.0%            
========================================
  Files          373     374     +1     
  Lines        19573   19261   -312     
========================================
- Hits         17420   17157   -263     
+ Misses        2153    2104    -49     

[KineticTheory]

LGTM.