cuda : CUDA GGML_OP_LIGHTNING_INDEXER implementation (generic vector kernel + wmma kernel) (#25545)

• cuda : CUDA GGML_OP_LIGHTNING_INDEXER implementation (generic vector kernel + wmma kernel)

• chore : remove indentation of #pragma unroll

• cuda : remove unnecessary kernel template declarations

• cuda : add WARPS_PER_BLOCK and K_VECS_PER_BLOCK template parameters in lightning indexer kernels to avoid duplication of constants.

• cuda : relax MMA architecture requirements to Turing in lightning indexer implementation

• chore : renamed variables

• chore : rename ggml_cuda_op_lightning_indexer() to ggml_cuda_lightning_indexer()

• chore : TODO for AMD rocWMMA

• chore : whitespace formatting

• chore : another variable rename to fix problems caused by shadowing

• chore : yet another rename, this time uppercased all constants

• cuda : added alignment checks for Q and K tensors in lightning indexer implementation

Co-authored-by: Stanisław Szymczyk [email protected]