[feature]: add `exclude_peer_pubkeys` in `AddInvoiceRequest`

[ZZiigguurraatt]

As a compliment to #1557, if we leave peer_pubkey empty, we should be able to set an array exclude_peer_pubkeys in AddInvoiceRequest. This would allow us to select all peers except certain ones to do an RFQ with and add to the route hints of an invoice.

[ZZiigguurraatt]

With #1613 incoming, we also need this for SendPayment.