Merge bitcoin/bitcoin#31333: fuzz: Implement G_TEST_GET_FULL_NAME

92d3d69 fuzz: Implement G_TEST_GET_FULL_NAME (Hodlinator)

Pull request description:

  Catching up to bench & unit tests. Makes for more orderly paths for fuzz tests using `BasicTestingSetup`.

  ### Before
  ```
  /tmp/test_common bitcoin/0748ae43ef8fa80703bc/regtest/blocks/xor.dat
  ```
  ### After
  ```
  /tmp/test_common bitcoin/tx_pool_standard/f18b3744625e0600eb0c/regtest/blocks/xor.dat
  ```

ACKs for top commit:
  kevkevinpal:
    ACK [92d3d69](bitcoin/bitcoin@92d3d69)
  furszy:
    utACK 92d3d69
  tdb3:
    ACK 92d3d69
  dergoegge:
    utACK 92d3d69
  brunoerg:
    code review ACK 92d3d69

Tree-SHA512: 5e83970b111232adece10f79e3a43d0c3c49ab635763e2a4b420f1336cbb8fee94aab751264ddec01ac8363166636e3b29cfe3b2969fc28c8dd6b31bda351950

src/test/fuzz/fuzz.cpp

@@ -35,8 +35,6 @@ __AFL_FUZZ_INIT();
 
 const std::function<void(const std::string&)> G_TEST_LOG_FUN{};
 
-const std::function<std::string()> G_TEST_GET_FULL_NAME{};
-
 /**
  * A copy of the command line arguments that start with `--`.
  * First `LLVMFuzzerInitialize()` is called, which saves the arguments to `g_args`.
@@ -80,6 +78,9 @@ void FuzzFrameworkRegisterTarget(std::string_view name, TypeTestOneInput target,
 static std::string_view g_fuzz_target;
 static const TypeTestOneInput* g_test_one_input{nullptr};
 
+const std::function<std::string()> G_TEST_GET_FULL_NAME{[]{
+    return std::string{g_fuzz_target};
+}};
 
 #if defined(__clang__) && defined(__linux__)
 extern "C" void __llvm_profile_reset_counters(void) __attribute__((weak));