Essentially moves the code in WalletView::setBitcoinGUI to the only caller.
Remove the circular dependency "qt/bitcoingui -> qt/walletview -> qt/bitcoingui"
This is a backport of Core PR17937 [2/2]
https://github.com/bitcoin/bitcoin/pull/17937/commits/cb8a86d9f952401eaad68b2e3818ce50f7befd91
Depends on D8698