Merge bitcoin-core/gui#858: qt: doc: adapt outdated binary paths to CMake changes

7ebc458 qt: doc: adapt outdated binary paths to CMake changes (Sebastian Falbesoner)

Pull request description:

  Adapt the qt-related instances of outdated binary paths to `./build/bin/...` (see [bitcoin#30454](bitcoin#30454) and the more recently merged [bitcoin#31161](bitcoin#31161)). According to `$ git grep src/qt.*bitcoin` there should be no more left to address.

ACKs for top commit:
  maflcko:
    lgtm ACK 7ebc458
  Sjors:
    utACK 7ebc458
  fanquake:
    ACK 7ebc458
  hebasto:
    ACK 7ebc458.

Tree-SHA512: 8cd6579fdf209ec4ee3c4c9cfb94cb11d5d5115068d31613d356ca1303214dc4461580535c2d3f2773f373a4271e9a82df25596d8369eef8235822f7030d88bd

Author: hebasto

src/qt/README.md

@@ -120,5 +120,5 @@ sudo apt-get install qtcreator
  - Under `Debuggers`: select `"GDB"` as debugger
 
 8. While in the `Projects` tab, ensure that you have the `bitcoin-qt` executable specified under `Run`
- - If the executable is not specified: click `"Choose..."`, navigate to `src/qt`, and select `bitcoin-qt`
+ - If the executable is not specified: click `"Choose..."`, navigate to `build/bin`, and select `bitcoin-qt`
 9. You're all set! Start developing, building, and debugging the Bitcoin Core GUI

src/qt/test/wallettests.cpp

@@ -268,9 +268,9 @@ struct MiniGUI {
 //
 // This also requires overriding the default minimal Qt platform:
 //
-//     QT_QPA_PLATFORM=xcb     src/qt/test/test_bitcoin-qt  # Linux
-//     QT_QPA_PLATFORM=windows src/qt/test/test_bitcoin-qt  # Windows
-//     QT_QPA_PLATFORM=cocoa   src/qt/test/test_bitcoin-qt  # macOS
+//     QT_QPA_PLATFORM=xcb     build/bin/test_bitcoin-qt  # Linux
+//     QT_QPA_PLATFORM=windows build/bin/test_bitcoin-qt  # Windows
+//     QT_QPA_PLATFORM=cocoa   build/bin/test_bitcoin-qt  # macOS
 void TestGUI(interfaces::Node& node, const std::shared_ptr<CWallet>& wallet)
 {
     // Create widgets for sending coins and listing transactions.