implement roi_aligned_rotated

[cregouby]

Current Situation

While managing rotated box, there is no way to perform ROI align pooling for rotated proposals.

Expected Situation

Implement and export the mmcv ROI align ops using C++ on CPU.
https://mmcv.readthedocs.io/en/latest/deployment/mmcv_ops_definition.html#mmcvroialignrotated