smite: move funding/commitment to channel_tx

[NishantBansal2003]

ref: #74 (comment)

[morehouse]

Do you plan to implement a transaction builder object as the name suggests?

[NishantBansal2003]

Do you plan to implement a transaction builder object as the name suggests?

Do we need that? I mean, I don't really see a need for a separate object that returns the constructed tx. I named it tx_builder because, in these modules, we are kind of building the tx, even though we are not explicitly returning it

If you think the name is confusing because of that, then I can change it to just transaction maybe?

[morehouse]

I'm not sure what the best name is, but it should probably have tx or transaction in it somewhere. "Builder" might imply some kind of builder pattern/object is contained within, which we currently don't have, and it also clashes a bit with the naming of future Build*Tx operations we'll implement. But having just transaction also collides with bitcoin::Transaction, and having just tx collides with bolt::tx_*.

So really it's all just bike-shedding. Whatever you think fits best works for me.

[morehouse]

LGTM