support wildcard domains from provider-db?

[r10s]

there seems to be at least one situation where wildcard domains would make things easier, https://github.com/deltachat/provider-db/pull/238 - so, unless sth. speaks totally against it, we should at least have a look how hard adding wildcard-support would be.

• supporting *. at the beginning of a domain would probably be sufficient, no need for complicated regex support, that would also affect performance somehow (and create more ambiguities)

[link2xt]

I'm even ok with hardcoded rewrite of anything that ends with .hermes.radio with hermes.radio during provider lookup.

We can generalize later if more providers require it.

[r10s]

closing, things seem to be fine for now.