GitLab

* [Dev] Implement IfStmtBinding and MergeIfStmt transformations

- Add IfStmtBinding to bind If statements to each statement in SeqStmt, enhancing the handling of conditional statements.
- Introduce MergeIfStmt to merge consecutive If statements within SeqStmt, optimizing the structure of conditional logic.
- Update phase.py to apply IfStmtBinding and MergeIfStmt transformations for the "sm_90" target.
- Enhance __init__.py with new functions for IfStmtBinding and MergeIfStmt, providing a clear interface for these transformations.

* Update license header in if_stmt_binding.cc

* Update license header in merge_if_stmt.cc

---------
Co-authored-by: Lei Wang <34334180+LeiWang1999@users.noreply.github.com>