* [Feature] Add vectorized float16 and float32 conversion support in CUDA codegen
* Implemented handling for conversions between float16 and float32 types, specifically for vectorized operations using __half22float2 and __float22half2_rn.
* Enhanced the existing code to support both directions of conversion based on the lane count.
* Improved overall type handling in the VisitExpr_ method for better compatibility with TileLang.
* [Feature] Add float32 to float8 conversion support in CUDA codegen
* Implemented handling for conversion from float32 to float8 (E4M3/E5M2) in the VisitExpr_ method.
* Added vectorized conversion support using __nv_cvt_float2_to_fp8x2 for float2 to fp8x2 transformations.
* Enhanced type handling for better compatibility with TileLang, particularly for float8 types.
* lint
* fix a bug
* [Enhancement] Support lanes=4 cases and add unit test for vectorized cast
* lint
* [Feature] Refactor bf16 convertion operations and remove legacy compile flags
* lint