Vulkan: Add Integer Dot Product mul_mat_vec shader for legacy quants (llama/14903)

Vulkan: Add Integer Dot Product mul_mat_vec shader for legacy quants (llama/14903)

* vulkan: Add Integer Dot Product mul_mat_vec shader for legacy quants

* vulkan: use subgroup operations for quantize_q8_1 shader

* vulkan: add q8_1_x4 type with 128-bit alignment, use in mul_mat_vecq shader

* vulkan: use q8_1_x4 blocks in mul_mmq shader

* vulkan: do 8 calculations per invocation instead of 32 in mul_mat_vecq, similar to mul_mat_vec

* vulkan: tune mul_mat_vecq performance for Intel

* vulkan: fix quantizing issue when tensor is not divisible by 128

* vulkan: adapt integer dot mmv to mmv small m optimization (llama/15355)

* vulkan: allow all subgroup modes for mmv and mmvq

* vulkan: use prealloc intermediate reuse for mmvq path

* vulkan: tune mmvq for Intel, AMD GCN and Nvidia RTX 3090

* vulkan: adapt mmv quantize_y path to conditional sync logic

* vulkan: disable q8_0 mmvq on Nvidia

* vulkan: enable q8_0 on Nvidia pre-turing

* fix prealloc sync condition

* fix llvmpipe subgroup 8 issue