refactor: split transform.hpp and rename rotate functions

[marciomoura]

This PR refactors ransform.hpp by splitting it into smaller, more focused headers and renames the
otate functions for better clarity.

Summary of changes:

• Extracted sum, max, min, and cross_product to math.hpp.
• Extracted SI <-> Per-Unit conversion logic to pu_conversion.hpp.
• Extracted unit casting utilities to quantity_cast.hpp.
• Renamed rotate to rotate_counter_clockwise and rotate_clockwise in abc, alphabeta, and dq frames.
• Updated mojito.hpp and mojito.cppm to reflect the new structure.
• Updated CMake and Bazel build files.
• Added comprehensive unit tests for all new/relocated functions.