Merge #15109: refactor: Use C++11 default member initializers

fa2510d5c1 Use C++11 default member initializers (MarcoFalke)

Pull request description:

  Changes:
  * Remove unused constructors that leave some members uninitialized
  * Remove manual initialization in each constructor and prefer C++11 default member initializers

  This is not a stylistic change, but a change that avoids bugs such as:

  *  fix uninitialized read when stringifying an addrLocal #14728
  *  qt: Initialize members in WalletModel #12426
  *  net: correctly initialize nMinPingUsecTime #6636
  * ...

Tree-SHA512: 0f896f3b9fcc464d5fc7525f7c86343ef9ce9fb13425fbc68e9a9728fd8710c2b4e2fd039ee08279ea41ff20fd92b7185cf5cca95a0bcb6a5340a1e6f03cae6b

src/test/addrman_tests.cpp

@@ -12,13 +12,9 @@
 
 class CAddrManTest : public CAddrMan
 {
-    uint64_t state;
-
 public:
     explicit CAddrManTest(bool makeDeterministic = true)
     {
-        state = 1;
-
         if (makeDeterministic) {
             //  Set addrman addr placement to be deterministic.
             MakeDeterministic();