Add visibility for pending mempool transactions

[sangbida]

When Core Lightning broadcasts a transaction, the funds effectively "disappear" from the user's perspective until the transaction confirms. This creates anxiety and uncertainty - users think their money is lost. This can be allieviated by providing visibility into pending transactions in the mempool.

[sangbida]

@michael1011 Just wanted to double check that you wanted pending incoming transactions to show up in list funds?

[michael1011]

Yes, incoming transactions that are not confirmed yet

[madelinevibes]

Sangbida is working on the b-watch plugin, work for this feature request should wait until the plugin is ready