[Feature]: Improve accuracy of "You will receive" amount in CJIT receive flow

[catch-21]

Describe the problem

During receive via CJIT flow, the "You will receive" value is now just an estimate due to recent changes preventing the correct amount being calculated. This is because Blocktank needs to know the LSP balance and client balance to calculate the fees, but the client balance is the amount minus the fees.

Describe the solution

Ideally, we show an accurate value in advance. If this is truly impossible then we could display a pessimistic value and hope no one cares enough about the inaccuracy because they got more than expected. Perhaps Blocktank can provide a worse-case yet still realistic value to use. Could also consider changing the text to "You will receive at least".

Additional context

No response