Remove send all button

[MaxHillebrand]

Currently in the first send dialog is the total wallet balance, and clicking on it pasts that amount to the send tab.

This makes a full wallet sweep easy and it suggests that it's a good thing. However, sending the entire balance is really bad, in the case the wallet contains both private and non-privat coins. And even when sending only private coins, consolidating many / all is a bad idea.

The suggestion is to remove the click & paste amount functionality.

[molnard]

#9295 (comment)

User can "destroy" their privacy by entering any amount that is forcing the wallet to select semi-private coins it is not related to the Max button. The only way to prevent that is the tx preview screen, where the user should realize if such a thing happens and reconsider.

[turbolay]

Some users might want to do a full wallet sweep for perfectly good reasons, I'm not sure it's a problem to help them. Most wallets I use have a "MAX" button, like BlueWallet. Maybe adding a warning would be a good solution for the privacy problem you're mentionning, but I would place it on the TxPreview screen.

User can "destroy" their privacy by entering any amount that is forcing the wallet to select semi-private coins it is not related to the Max button. The only way to prevent that is the tx preview screen, where the user should realize if such a thing happens and reconsider.

cc #9279

We are facing again and again and again the problem of "We do not help the user in knowing the amount he can privately send to a specific address" because of the assumption that "users only spend at 100% privacy".

The most recent occurence of the issues related to this is #10739 -> We can't really merge this PR, because it would mean that balance will contain small unmixed UTXOs and it might be extremely difficult for the user to know how much he can send without including an unmixed coin.

Imagine you have 1.23456789 coins private and 0.45678912 non mixed. You want to send all your private money which is a perfectly fine behavior, how can you do it considering you only see your total balance of 1.69135701 and that you have 27% privacy ??? You have to use the calculator or something like that and will never end up with the exact number. Note that Im willingly excluding ctrl+c+d as it's not a standard feature.