Dynamic bitset blocks size should not be configurable and be a single byte

[Alex-PLACET]

Currently, it's possible to choose any size for the blocks in the Dynamic bitset's template argument, but in the apache arrow documentation: https://arrow.apache.org/docs/dev/format/Columnar.html#validity-bitmaps
But using a block size greater than a byte will lead to endianess issues

[Klaim]

dynamic_bitest itself is a generic type, it's not designed to be specific to arrow. It's usage in the library, for example there, here the block size is 8bit, which matches the spec, isnt it? It can't be changed by the user AFAIK.

[Alex-PLACET]

In that case, it requires modifications to works on big endian architectures. I don't know if we really want to add complexity for cases we don't use.