Allow to override config defaults for inbound channels on a per-channel basis

[tnull]

Currently our manual channel acceptance interface doesn't allow us to override any config defaults on a per channel basis, i.e., users can only accept or fail the inbound channel request, not set any specific parameters.

We should allow this.

[tnull]

Assigning myself for now, hope to pick this up soonish.

[TheBlueMatt]

I guess we should add a trivial channel config update parameter to the channel acceptance method?

[tnull]

I guess we should add a trivial channel config update parameter to the channel acceptance method?

Yeah, that or breaking up the current config object into parts that are static and parts that can be changed by the acceptor at this point. FWIW, some refactoring there could also help users understand who determines what limits, for example.

[joostjager]

Going down the route of adding a config override struct parameter to the accept methods, and from there see if the main config struct can be refactored in a nice way.