Add notifications for payed LN invoice/incoming Ecash from Nostr

[KKA11010]

Is your feature request related to a problem? Please describe.

• I don't see when an invoice is paid after leaving the invoice screen.
• I can't leave the "processing/loading" screen after performing a melt/swap request
• I have to manually check for Ecash in Nostr dms

related issue: #245

Describe the solution you'd like

• Show a toaster while app is open. If app is in the background, show native mobile notification.
• update tx entry in history by adding a pending state and update the pending state accordingly