Merge bitcoin-core/gui#202: peers-tab: bug fix right panel toggle

8353e8cecc peers-tab: bug fix right panel toggle (randymcmillan)

Pull request description:

  Initial Presentation:

  ![Screen Shot 2021-01-28 at 8 36 15 PM](https://user-images.githubusercontent.com/152159/106220159-e2a81b80-61a8-11eb-84e9-f9b44375c9a1.png)

  When node row selected - panel is presented:

  ![Screen Shot 2021-01-28 at 8 36 22 PM](https://user-images.githubusercontent.com/152159/106220185-eb98ed00-61a8-11eb-9467-6a762941902d.png)

  When network disabled - right panel is hidden:

  ![Screen Shot 2021-01-28 at 8 36 32 PM](https://user-images.githubusercontent.com/152159/106220235-0a977f00-61a9-11eb-8a10-f31e4312ed31.png)

ACKs for top commit:
  jarolrod:
    ACK 8353e8cecc
  jonatack:
    ACK 8353e8cecc tested rebased on current master. Behavior is initially a bit surprising but this would allow more columns to be added to the peers tab window. Verified that selecting more than one peer, clicking on a column header, or running `disconnectnode "" <currently-selected-peer-id>` in the console (or on the CLI with the `-server` startup option) returns the window to its full size. If this is merged, it might be nice to have an obvious way to close the details area like a clickable "close this" icon in the upper left corner of the area.
  Talkless:
    tACK 8353e8cecc, tested on Debian Sid. Made `bitcoind` connect to `bitcoin-qt` with the PR changes, and after I quit the `bitcoind` instance, right panel do disappear, compared to the previous commit where it didn't.

Tree-SHA512: 8fc156f40bdd61e3ba8db333c729a2a07fd5f0fd1eed56f2fd2aa5ae5864756f8ab6fad74ae2fb0552ee7518b6d489f5800709e6c80c6f31f61fd8ce21cece5f

src/qt/forms/debugwindow.ui

@@ -988,7 +988,7 @@
            </item>
           </layout>
          </widget>
-         <widget class="QWidget" name="widget_2" native="true">
+         <widget class="QWidget" name="peersTabRightPanel" native="true">
           <property name="sizePolicy">
            <sizepolicy hsizetype="Minimum" vsizetype="Preferred">
             <horstretch>0</horstretch>