wip: feat: more generic primary module

[maan2003]

replace primary module with balance provider.

this is more flexible, you can use inputs from multiple modules

example: you have mint-v2 and mint modules, you can inputs from both mint and mint-v2, but only use output of mint-v2.

[elsirion]

Should be coordinated with #4477. @joschisan thoughts on this proposal to make the primary module concept more flexible?

[justinmoon]

added "needs further review" b/c might be good tuesday topic