Add on chain for federations

[TonyGiorgio]

TODO:

• [x] Withdrawals
• [x] Frontend needs to allow withdrawals from fedimint balance
• [x] Change APIs to account for withdraw pending
• [x] Figure out max send situation
• [x] Monitor eventual TXID for confirmations (fedimint doesn't care about tracking it)
• [x] Lots of TODOs in the on chain cleanup in federation.rs
• [x] pull activity list for on chain addresses
• [x] Refreshing doesn't show on chain history
• [x] activity item for on chain deposit doesn't show additional info
• [x] tests for activity item & indexing
• [x] subscribe to pending on chain operations
• [x] show payment details on the onchain send screen when the link is clicked
• [x] handle tiny amounts properly if they are attempted to be paid

[TonyGiorgio]

This works as long as you don't try to send max. Still a lot of code to clean up and want to do some tests.

There's some possible ideas for frontend changes too but will think about them more.

• we should say not to send more than once to the address
• we should tell them it requires 10 confs for deposits
• we should probably show a fee to confirm before sending

[TonyGiorgio]

I want to do some tests for the activity item stuff but this is ready for review

[TonyGiorgio]

READY