Merge bitcoin-core/gui#447: Never disable HD status icon

35e814c qt: never disable HD status icon (=)

Pull request description:

  [bitcoin#8517](bitcoin#8517) introduced the HD status icon in the bottom menu bar. At the time, it may have made sense to disable the HD status icon (which would display the icon at 50% opacity) when the wallet is not HD or watch-only.

  Since then, we have had many changes to our UI. Namely, the ability to switch between dark and light mode on macOS. Additionally, since version 0.16, the Bitcoin Core client only [generates HD wallets](bitcoin#12547). Non-HD Wallets cannot be created anymore, only imported.

  This PR proposes never to disable the HD status icon in the bottom menu bar. Instead, we always leave the HD status icon enabled for a better user interface. There’s no good reason for it to remain disabled, and it’s hard to see the watch-only icon in macOS dark mode. If a user has imported a non-HD wallet, we also want the icon to be as clear as possible in the bottom menu bar.

  - on macOS

  |                        |      Master      |         PR           |
  | ------------- | ------------- | ------------- |
  |  Dark Mode    | ![unnamed](https://user-images.githubusercontent.com/44024636/136088058-7eece199-0e6d-4bd3-91d5-8e04b6ccdd32.png)  | ![unnamed-2](https://user-images.githubusercontent.com/44024636/136088203-7704bd25-f822-4489-b023-7acc935698c9.png) |
  |  Light Mode   |![unnamed-3](https://user-images.githubusercontent.com/44024636/136088441-a6abcf9d-f2ca-4b6d-96d4-14487dad30c0.png)| ![unnamed-4](https://user-images.githubusercontent.com/44024636/136088539-f61fb93d-63d3-4f3f-908d-1c51e8b0f670.png)|
  - on ubuntu 20.04

  |      Master      |         PR           |
  | ------------- | ------------- |
  |   ![Screenshot 2021-10-06 at 3 15 12 AM](https://user-images.githubusercontent.com/44024636/136107153-cc00cefc-1ae5-4923-ab8c-f4e8ca2447a1.png) |  ![Screenshot 2021-10-06 at 3 18 20 AM](https://user-images.githubusercontent.com/44024636/136107479-96cb487d-171f-4e11-b1c2-cb3e4109d56f.png)|

ACKs for top commit:
  jarolrod:
    ACK 35e814c
  hebasto:
    ACK 35e814c

Tree-SHA512: ba7d1c1f2a439bbb32f7755c10cadc5d61892add3abca2a286a30a0fbbbb077e2190365c9e8dee6a10b4feed249656c7bd58ea14a319f5b28cd56182d4ddbdc1

Author: hebasto

src/qt/bitcoingui.cpp

@@ -1304,8 +1304,6 @@ void BitcoinGUI::setHDStatus(bool privkeyDisabled, int hdEnabled)
     labelWalletHDStatusIcon->setThemedPixmap(privkeyDisabled ? QStringLiteral(":/icons/eye") : hdEnabled ? QStringLiteral(":/icons/hd_enabled") : QStringLiteral(":/icons/hd_disabled"), STATUSBAR_ICONSIZE, STATUSBAR_ICONSIZE);
     labelWalletHDStatusIcon->setToolTip(privkeyDisabled ? tr("Private key <b>disabled</b>") : hdEnabled ? tr("HD key generation is <b>enabled</b>") : tr("HD key generation is <b>disabled</b>"));
     labelWalletHDStatusIcon->show();
-    // eventually disable the QLabel to set its opacity to 50%
-    labelWalletHDStatusIcon->setEnabled(hdEnabled);
 }
 
 void BitcoinGUI::setEncryptionStatus(int status)