fix(send,receive): drop the corner doge that painted over the forms

IdleDoge scaled its movie from `currentImage()` after `jumpToFrame(0)`, but the
first frame is not decoded at that point, so the size came back null, the
scaling was skipped, and the QLabel ended up at the GIF's full 500x397. Parked
at the bottom-right of the form it painted an opaque 500x397 slab of window
background over the lower half of Send and over the Receive address table.

Send is the screen where money leaves the wallet; it does not get an overlay
sitting on top of the address and amount fields at all. Receive loses it for
the same reason. SendWidget.cpp and ReceiveWidget.cpp are back to exactly their
pre-ambient state, and the widget is removed rather than left unused.

The ambient scene keeps the places where it has its own real estate: the lock
screen, the History banner, and the mining tab.

src/ReceiveWidget.cpp

@@ -12,7 +12,6 @@
 #include "utils/config.h"
 #include "utils/Icons.h"
 #include "utils/Utils.h"
-#include "widgets/IdleDoge.h"
 
 ReceiveWidget::ReceiveWidget(Wallet *wallet, QWidget *parent)
         : QWidget(parent)
@@ -21,8 +20,6 @@ ReceiveWidget::ReceiveWidget(Wallet *wallet, QWidget *parent)
 {
     ui->setupUi(this);
 
-    new IdleDoge(this);   // wowlet: whisper-quiet corner critter (freezes when reduced-motion)
-
     m_model = m_wallet->subaddressModel();
     m_proxyModel = new SubaddressProxyModel(this, m_wallet->subaddress());
     m_proxyModel->setSourceModel(m_model);

src/SendWidget.cpp

@@ -11,7 +11,6 @@
 #include "Icons.h"
 #include "libwalletqt/Wallet.h"
 #include "libwalletqt/WalletManager.h"
-#include "widgets/IdleDoge.h"
 
 #if defined(WITH_SCANNER)
 #include "wizard/offline_tx_signing/OfflineTxSigningWizard.h"
@@ -26,8 +25,6 @@ SendWidget::SendWidget(Wallet *wallet, QWidget *parent)
 {
     ui->setupUi(this);
 
-    new IdleDoge(this);   // wowlet: whisper-quiet corner critter (freezes when reduced-motion)
-
     QString amount_rx = R"(^\d{0,8}[\.,]\d{0,12}|(all)$)";
     QRegularExpression rx;
     rx.setPattern(amount_rx);