scripted-diff: refactor: CWallet::Create() -> CreateNew()

Aside from being more legible, changing the name of `CWallet::Create()`
also validates that every instance where a new wallet is `Create()`'ed
is handled in this branch.

-BEGIN VERIFY SCRIPT-
sed -i 's|\bCreate(|CreateNew(|g' src/wallet/wallet.cpp  src/wallet/wallet.h  src/wallet/test/util.cpp src/wallet/test/wallet_tests.cpp
-END VERIFY SCRIPT-

src/wallet/test/wallet_tests.cpp

@@ -559,7 +559,7 @@ BOOST_FIXTURE_TEST_CASE(wallet_descriptor_test, BasicTestingSetup)
     BOOST_CHECK_EXCEPTION(vr >> w_desc, std::ios_base::failure, malformed_descriptor);
 }
 
-//! Test CWallet::Create() and its behavior handling potential race
+//! Test CWallet::CreateNew() and its behavior handling potential race
 //! conditions if it's called the same time an incoming transaction shows up in
 //! the mempool or a new block.
 //!