Fix kwargs and scoping in @polynomial_ring

[mgkurtz]

See the new tests for examples now working.

[fingolfin]

Thanks! Could you please also add a test that verifies it works now (and that it stays working)? It shouldn't be too hard, you can just do what the issues describes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.94%. Comparing base (42192d8) to head (094c8d4).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1633   +/-   ##
=======================================
  Coverage   86.94%   86.94%           
=======================================
  Files         114      114           
  Lines       29697    29700    +3     
=======================================
+ Hits        25820    25823    +3     
  Misses       3877     3877           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[mgkurtz]

Added several tests. Rewrote keyword argument handling to fix #1631 also in the case of polynomial_ring(QQ, ["x", "y"], internal_ordering=:lex) with comma instead of semicolon and to handle polynomial_ring(K, ["x", "y"]; internal_ordering=ordering) with K and ordering some variables to be evaluated in current scope.

[fingolfin]

Awesome, thank you for the quick fix!