On master (e75f91eae3936269b40b4bfdfe540d5526270936) not using layout manager causes problems with resizing:

Also text labels are not resized properly on some window managers (https://github.com/bitcoin/bitcoin/issues/20777), or if their lengths are changed (after translation).
This PR introduces a standard layout manager for the "Create Wallet" dialog that fixes all layout issues (actually, the createwalletdialog.ui has been re-written from scratch):

Additional visual changes:
- advanced options are grouped in
QGroupBox(https://github.com/bitcoin-core/gui/pull/96#issuecomment-726337165) - enabled the size grip


