replace disable freebies with a base fee setting

[riccardobl]

Describe the problem you're trying to solve

Paying 1 sats fee with attached wallets without a direct channel and appropriate min htlc might fail, as per #1604

Describe the solution you'd like

I'm not sure what the best name for this feature would be to avoid confusion, but the idea is to replace the "disable freebies" setting with a configurable field. This field would allow users to set the minimum amount they are willing to pay to post.
It could be set to 0 for freebies or a higher amount that could serve as a donation to Stacker News or the territory.

Describe alternatives you've considered

No response

Additional context

No response

[ekzyis]

Mhh, I understand the problem but I think the solution would be to have automated top-up (inverse of autowithdrawals) so you always have some CCs for small payments.