Move guassopt to optics/guassopt

Correct import in test_gaussopt

Correct imports in docstrings
Correct implicit import
Change location of docs
Remove merge conflicts
Add deprecation warning for sympy.physics.gaussopt
Change Google code to GitHub in SymPyDecprecationWarning docstring
Add issue number(7659) in the deprecation warning
Do not test duplicate gaussopt.py file
Skip physics/gaussopt.py for doctest
Merge pull request #7607 from debugger22/move-gaussopt

Move guassopt to optics/guassopt
Add function to calculate transmitted vector after refraction [skip ci]
Change the name of function to refraction_angle and fix a typo [skip ci]
Make refraction_angle compatible with Ray3D and plane. [skip ci]
Add documentation file for utils.py. [skip ci]