rpc: move WALLET_FLAG_CAVEATS to the compilation unit of its caller

and add the walletutil.h include header for WALLET_FLAG_AVOID_REUSE that was
already missing before this change.

WALLET_FLAG_CAVEATS is only used in one RPC, so no need to encumber wallet.h and
wallet.cpp with it, along with all of the files that include wallet.h during
their compilation. Also apply clang-format per:

git diff -U0 HEAD~1.. | ./contrib/devtools/clang-format-diff.py -p1 -i -v

Author: jonatack

src/wallet/rpc/wallet.cpp

@@ -13,13 +13,22 @@
 #include <wallet/rpc/wallet.h>
 #include <wallet/rpc/util.h>
 #include <wallet/wallet.h>
+#include <wallet/walletutil.h>
 
 #include <optional>
 
 #include <univalue.h>
 
 
 namespace wallet {
+
+static const std::map<uint64_t, std::string> WALLET_FLAG_CAVEATS{
+    {WALLET_FLAG_AVOID_REUSE,
+     "You need to rescan the blockchain in order to correctly mark used "
+     "destinations in the past. Until this is done, some destinations may "
+     "be considered unused, even if the opposite is the case."},
+};
+
 /** Checks if a CKey is in the given CWallet compressed or otherwise*/
 bool HaveKey(const SigningProvider& wallet, const CKey& key)
 {

src/wallet/wallet.cpp

@@ -51,13 +51,6 @@
 using interfaces::FoundBlock;
 
 namespace wallet {
-const std::map<uint64_t,std::string> WALLET_FLAG_CAVEATS{
-    {WALLET_FLAG_AVOID_REUSE,
-        "You need to rescan the blockchain in order to correctly mark used "
-        "destinations in the past. Until this is done, some destinations may "
-        "be considered unused, even if the opposite is the case."
-    },
-};
 
 bool AddWalletSetting(interfaces::Chain& chain, const std::string& wallet_name)
 {

src/wallet/wallet.h

@@ -145,8 +145,6 @@ static const std::map<std::string,WalletFlags> WALLET_FLAG_MAP{
     {"external_signer", WALLET_FLAG_EXTERNAL_SIGNER}
 };
 
-extern const std::map<uint64_t,std::string> WALLET_FLAG_CAVEATS;
-
 /** A wrapper to reserve an address from a wallet
  *
  * ReserveDestination is used to reserve an address.