Foundation Classes, gp - Mark core types and methods constexpr/noexcept (#790)

Foundation Classes, gp - Mark core types and methods constexpr/noexcept (#790)

Make gp basic types and operations more constexpr-friendly and noexcept:
- Mark gp::Resolution as constexpr.
- Add constexpr and/or noexcept to many constructors and small access/modifier methods.
- Convert several functions to constexpr where safe to allow compile-time evaluation.
- Initialize members via initializer lists for several GTrsf/GTrsf2d/Mat/etc constructors.
- Add noexcept to transformation/serialization helpers and small utilities where appropriate.

This enables better compile-time optimizations and safer noexcept semantics across TKMath gp primitives.