vvc_deblock: add AVX2-accelerated chroma deblock filter

[zackerthescar]

[refact] tests/checkasm/checkasm --test=vvc_deblock --benchmark                                                                                                                      deblock_chroma 
benchmarking with native FFmpeg timers
nop: 48.9
checkasm: using random seed 189563177
AVX2:
 - vvc_deblock.chroma [OK]
checkasm: all 4 tests passed
vvc_h_loop_filter_chroma8 weak_c: 50.7
vvc_h_loop_filter_chroma8 weak_avx2: 14.7
vvc_h_loop_filter_chroma10 weak_c: 50.7
vvc_h_loop_filter_chroma10 weak_avx2: 5.7
vvc_v_loop_filter_chroma8_c: 41.7
vvc_v_loop_filter_chroma8_avx2: 32.7
vvc_v_loop_filter_chroma10_c: 41.7
vvc_v_loop_filter_chroma10_avx2: 32.7

Currently does not pass most conformance tests, which suggests an issue with both my code and my checkasm impl.

[zackerthescar]

Benchmark results

File	C	AVX2
BQTerrace_1920x1080_60_10_420_22_RA.vvc	74.0	76.3
RitualDance_1920x1080_60_10_420_37_RA.266	119.7	131.3
RitualDance_1920x1080_60_10_420_32_LD.266	120.0	123.7
Chimera_8bit_1080P_1000_frames.vvc	155.0	156.3
Tango2_3840x2160_60_10_420_27_LD.266	31.3	32.7
NovosobornayaSquare_1920x1080.bin	151.7	151.7

[FFmpeg] tests/checkasm/checkasm --test=vvc_deblock --benchmark
benchmarking with native FFmpeg timers
nop: 49.2
checkasm: using random seed 1714318218
AVX2:
 - vvc_deblock.chroma [OK]
checkasm: all 6 tests passed
vvc_h_loop_filter_chroma_8_c: 50.7
vvc_h_loop_filter_chroma_8_avx2: 14.7
vvc_h_loop_filter_chroma_10_c: 41.7
vvc_h_loop_filter_chroma_10_avx2: 5.7
vvc_h_loop_filter_chroma_12_c: 41.7
vvc_h_loop_filter_chroma_12_avx2: 14.7
vvc_v_loop_filter_chroma_8_c: 50.7
vvc_v_loop_filter_chroma_8_avx2: 23.7
vvc_v_loop_filter_chroma_10_c: 41.7
vvc_v_loop_filter_chroma_10_avx2: 23.7
vvc_v_loop_filter_chroma_12_c: 41.7
vvc_v_loop_filter_chroma_12_avx2: 32.7

[zackerthescar]

I have no clue why the test is failing here. For reference, the checkasm test passes fully on my Arch Linux system. (checkasm will not benchmark if it fails)