Display fee rate in sat/vB on onchain transaction receipt

[alltheseas]

user story

As a Blixt wallet user who just tapped "withdraw" and is viewing the associated onchain transaction history, in addition to the current details and adjacent to the absolute Fees number I would like to see the fee rate in sat/vB, so that I can gauge if my transaction is stuck / will show up in the mempool due to insufficient transaction fees.

acceptance criteria

1. I can see in sat/vB the fee rate I submitted for my onchain withdrawal request in the onchain transaction details view

napkin sketch mockup

[hsjoberg]

Great idea