Support binding math constants

[Repiteo]

• Relevant RC Thread

Enables the ability to bind ±pi, ±tau, ±inf, and nan values. Previously the binding generator would try to pass these aliases directly to C++, causing build errors:

Error: /home/runner/work/godot/godot/godot-cpp/gen/include/godot_cpp/classes/tween.hpp:117:72: error: 'inf' was not declared in this scope; did you mean 'ynf'?
  117 |         Ref<Tween> set_trans_params(double p_param1, double p_param2 = inf);
      |                                                                        ^~~
      |                                                                        ynf

After these changes, this would result in:

Ref<Tween> set_trans_params(double p_param1, double p_param2 = Math_INF);

[dsnopek]

Thanks!

Overall, this makes sense. However, on godotengine/godot#82155 it's only making it so that Godot can generate "inf" or "-inf" - Godot can't generate any of the others added in this PR. I think there should be a PR (that's likely to be merged) on the Godot side for all of these before we merge support for them into godot-cpp.