Merge #12610: Multiwallet for the GUI

779c5f984 Qt: hide RPCConsole wallet selector when no wallets are present (Jonas Schnelli)
dc6f150f3 Qt: show wallet name in request dlg in case of multiwallet (Jonas Schnelli)
4826ca4b8 Qt: show wallet name in send confirmation dlg in case of multiwallet (Jonas Schnelli)
cfa4133ce GUI: RPCConsole: Log wallet changes (Luke Dashjr)
b6d04fc7c Qt: Get wallet name from WalletModel rather than passing it around (Luke Dashjr)
12d8d2681 Qt: When multiple wallets are used, include in notifications the name (Jonas Schnelli)
d1ec34a76 Qt: QComboBox::setVisible doesn't work in toolbars, so defer adding it at all until needed (Luke Dashjr)
d49cc70e6 Qt: Add wallet selector to debug console (Jonas Schnelli)
d558f44c5 Bugfix: RPC: Add missing UnregisterHTTPHandler for /wallet/ (Luke Dashjr)
85d531971 Qt: Ensure UI updates only come from the currently selected walletView (Luke Dashjr)
e449f9a9e Qt: Add a combobox to toolbar to select from multiple wallets (Luke Dashjr)
3dba3c3ac Qt: Load all wallets into WalletModels (Luke Dashjr)

Pull request description:

  This is an overhaul of #11383 (plus some additions).
  It avoids unnecessary coupling of httpserver/jsonrpc and the wallet as well as it avoids pointer pure passing (and pointer deletion) of `CWallet` (plus other minor design changes).

  Additionally it adds the wallet name to the sendconfirmation and request dialog (in case multiwallet is active)

Tree-SHA512: 3d06e18badbc5d1821e488bf1dae463bb0be544cf11b2b618e025812bfdd13c5f39604bb93b4c705313930e7dc4e66f4848b9469ba14871bade58e7a027246a1

src/qt/forms/debugwindow.ui

@@ -412,6 +412,22 @@
          <property name="spacing">
           <number>4</number>
          </property>
+         <item>
+          <widget class="QLabel" name="WalletSelectorLabel">
+           <property name="text">
+            <string>Wallet: </string>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QComboBox" name="WalletSelector">
+           <item>
+            <property name="text">
+             <string>(none)</string>
+            </property>
+           </item>
+          </widget>
+         </item>
          <item>
           <spacer name="horizontalSpacer">
            <property name="orientation">