Merge #20530: lint, refactor: Update cppcheck linter to c++17 and improve explicit usage

1e62350ca20898189904a88dfef9ea11ddcd8626 refactor: Improve use of explicit keyword (Fabian Jahr)
c502a6dbfb854ca827a5a3925394f9e09d29b898 lint: Use c++17 std in cppcheck linter (Fabian Jahr)

Pull request description:

  I found the `extended-lint-cppcheck` linter still uses `std=c++11` when reviewing #20471. The only difference in the output after this change is one line is missing:

  ```
  src/script/descriptor.cpp:159:5: warning: Struct 'PubkeyProvider' has a constructor with 1 argument that is not explicit. [noExplicitConstructor]
  ```

  After some digging, I am still not sure why this one is ignored with c++17 when 40 other`noExplicitConstructor` warnings were still appearing.

  In the second commit, I fix these warnings, adding `explicit` where appropriate and adding fixes to ignore otherwise.

ACKs for top commit:
  practicalswift:
    cr ACK 1e62350ca20898189904a88dfef9ea11ddcd8626: patch looks correct!
  MarcoFalke:
    review ACK 1e62350ca20898189904a88dfef9ea11ddcd8626

Tree-SHA512: dff7b324429a57160e217cf38d9ddbb6e70c6cb3d3e3e0bd4013d88e07afc2292c3df94d0acf7122e9d486322821682ecf15c8f2724a78667764c05d47f89a12

3 files changed, 3 insertions, 3 deletions

diff --git a/src/qt/test/addressbooktests.h b/src/qt/test/addressbooktests.h
index 5de89c7592..e6d24f202f 100644
--- a/src/qt/test/addressbooktests.h
+++ b/src/qt/test/addressbooktests.h
@@ -15,7 +15,7 @@ class Node;
 class AddressBookTests : public QObject
 {
 public:
-    AddressBookTests(interfaces::Node& node) : m_node(node) {}
+    explicit AddressBookTests(interfaces::Node& node) : m_node(node) {}
     interfaces::Node& m_node;
 
     Q_OBJECT
diff --git a/src/qt/test/rpcnestedtests.h b/src/qt/test/rpcnestedtests.h
index 0a00d1113a..320275129d 100644
--- a/src/qt/test/rpcnestedtests.h
+++ b/src/qt/test/rpcnestedtests.h
@@ -15,7 +15,7 @@ class Node;
 class RPCNestedTests : public QObject
 {
 public:
-    RPCNestedTests(interfaces::Node& node) : m_node(node) {}
+    explicit RPCNestedTests(interfaces::Node& node) : m_node(node) {}
     interfaces::Node& m_node;
 
     Q_OBJECT
diff --git a/src/qt/test/wallettests.h b/src/qt/test/wallettests.h
index 8ee40bf07f..dfca3370f7 100644
--- a/src/qt/test/wallettests.h
+++ b/src/qt/test/wallettests.h
@@ -15,7 +15,7 @@ class Node;
 class WalletTests : public QObject
 {
  public:
-    WalletTests(interfaces::Node& node) : m_node(node) {}
+    explicit WalletTests(interfaces::Node& node) : m_node(node) {}
     interfaces::Node& m_node;
 
     Q_OBJECT