Ensure that property setters are used in CylindricalMesh and SphericalMesh

[paulromano]

Description

I noticed that the constructors for CylindricalMesh and SphericalMesh were directly setting _r_grid, _phi_grid, etc. instead of going through the properties, which perform checks on the values. This PR fixes and makes corresponding changes in the tests.

I've also included a few small fixes for warnings that were being raised during tests.

Checklist

• I have performed a self-review of my own code
• I have run clang-format on any C++ source files (if applicable)
• I have followed the style guidelines for Python source files (if applicable)
• I have made corresponding changes to the documentation (if applicable)
• I have added tests that prove my fix is effective or that my feature works (if applicable)

[pshriwise]

Thanks for these updates @paulromano. 🧇's rule.