Breaking Changes

Payments table is deleted as part of the migration.
Now we use internal transactions. Transactions from the individual LNClients are NOT migrated.

What this enables

[x] more transaction list metadata - which app made or received which payment
[x] removes broken constraint between request events and payments (see https://github.com/getAlby/nostr-wallet-connect-next/pull/388)
[ ] fee and transaction states are saved internally, so improved budgeting and database transactions around payments are possible. See https://github.com/getAlby/nostr-wallet-connect-next/issues/279

New Transactions Layer (layer between api/nip-47 handlers and LN clients)
- Creating a transaction will internall call the LNClient to create the transaction, then save it to our DB with additional metadata, such as the app the transaction was made for.
LNClient
- (TBC) checkUnsettledTransaction(s) functions can be used for backends that do not receive events for updates. Alternative: background sync task
  Database
New transaction table with additional data than the old payment table, notably:
- type incoming or outgoing
- state which can be used to ensure budgets are not exceeded
- metadata JSON-encoded transaction metadata

TODOs:

[x] update all transaction related usages of lnclient to go through transactions service
[ ] Test payment timeouts correctly apply to transactions
[x] Add fees to budget calculation
[ ] Keysend
[ ] Test payment metadata
[ ] Review unique constraints
- [ ] Duplicate payments for the same payment hash are possible if a payment fails and we retry - or should we update the existing record? then there can be a constraint: appId + paymentHash
[ ] Should the internal wallet have it's own app ID?
[ ] NIP-47 notifier receives a notification of a payment, but we do not know the app ID - test both for apps and global view
- [ ] notifier should be updated to check if the transaction app ID matches the app ID, or it's an app with a global view
[x] remove old payments table
[ ] review it's ok NOT to migrate transaction history. I would email all early users and let them know.

To move to new issue: