Speed up truffle with 256b TBL instructions

256b wide SVE vectors allow some simplification of truffle.
Up to 40% speedup on graviton3. Going from 12500 MB/s to 17000 MB/s
onhe microbenchmark.
SVE2 also offer this capability for 128b vector with a speedup around
25% compared to normal SVE

Add unit tests and benchmark for this wide variant

Signed-off-by: Yoan Picchi <yoan.picchi@arm.com>

unit/CMakeLists.txt

@@ -107,6 +107,7 @@ set(unit_internal_SOURCES
     internal/shufti.cpp
     internal/state_compress.cpp
     internal/truffle.cpp
+    internal/truffleWide.cpp
     internal/unaligned.cpp
     internal/unicode_set.cpp
     internal/uniform_ops.cpp