feat: make write_empty_chunks dynamic

[LDeakin]

No description provided.

[ilan-gold]

Looking at the zarr-python code, it seems that this sort of thing is tied to Array creation which is less dynamic than I would have thought i.e., instead of using the write_empty_chunks config value directly from the config itself. But I assume the goal of this PR is to just simplify what we're doing here and move closer to zarr-python if not perfectly aligned?

[d-v-b]

i think eventually in zarr-python we want to support an API where the array config can be locally overridden. The logic for this is that you might want different empty chunks behavior across the domain of the same array. but we haven't pieced together an API for this yet.

[ilan-gold]

Thanks for the clarification @d-v-b, so then I think this PR seems reasonable then, although https://github.com/zarrs/zarrs-python/pull/103/files#diff-ac216671a3198674cfb77afda777ffa112d2f3c343775adfbbcba98a87216a8fR164-R172 is a little worrying. Is it possible for multiple selections to have different values?

[LDeakin]

I picked this up when I was trying to determine whether we wanted ArrayConfig on construction or not for zarr-developers/zarr-python#3233. Our docs on this were incorrect before anyway

[ilan-gold]

I guess we couldn't do per-chunk write_empty_chunks anyway given that the CodecOptions are created once and then reused