[feat(ring_theory/dedekind_domain/selmer_group): add Selmer groups of Dedekind domains](https://github.com/leanprover- community/mathlib/commit/9aec1a288c6222ef5ccfd02a07155e9dd37b20de) (mathlib#15405)
Authored-by: Multramate [(commit)](https://github.com/leanprover- community/mathlib/commit/9aec1a288c6222ef5ccfd02a07155e9dd37b20de)