Remove automatic fee setting to avoid bugs/money loss

[MatthewCroughan]

If we remove whatever code is responsible for automatic fee setting, then issue #5575 in principal cannot occur, as the only fee value/variable in memory possible to set will be taken from the user via the GUI, and in the worst case be set to NULL.

The variable should be initialized to NULL, then look up what the user has set. It should not be set from any other source automatically outside of the user's control.

I would prefer this guarantee to lost money, especially for a wallet as specifically power-user oriented as Bisq.

Instead, can we have a variable that shows a suggested fee, rather than setting the fee on behalf of the user automatically at any stage? It should be required that the user set the fee, in order to avoid possible bugs with the GUI.

It would be better if the default automated fee variable were only set upon hitting the "send transaction" button, rather than being set somewhere in memory prior to user interaction, automatically, as seems to be the case. I could be wrong about this implementation, it seems logical that this is what is happening however.

If the default fee is set prior to user interaction, in a variable that is controlled separately from the GUI, it can lead to this issue in principal.

I do not have the time to look into the code clearly, but my observations might make some sense, I hope they are of use and not completely inaccurate.