direct cdivsufsort usage and avoid reallocations when constructing sa

[x100111010]

• replaced the suffix_array crate with direct sa building which allows for simple switching between cdivsufsort and divsufsort in rust by Amos Wenger @fasterthanlime
• crate: cdivsufsort (Rust bindings for Yuta Mori's divsufsort) remains the fastest single threaded Suffix Array construction implementation. cdivsufsort is about +15% faster compared to the rust port
• c193ef9 avoid reallocations when constructing suffix array - results in a +7% performance gain
• added rustfmt config