[backport#17999 1/2] Add ChainClient setMockTime, getWallets methods

Summary:
Needed to set mock times, and get wallet interface pointers correctly when
wallet code is running in a different process from node code.

---

bitcoin/bitcoin@1dde238

Partial backport of Core [[bitcoin/bitcoin#17999 | PR17999]]

Test Plan:
  ninja check check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6995

src/interfaces/chain.h

@@ -335,6 +335,12 @@ class ChainClient {
 
     //! Shut down client.
     virtual void stop() = 0;
+
+    //! Set mock time.
+    virtual void setMockTime(int64_t time) = 0;
+
+    //! Return interfaces for accessing wallets (if any).
+    virtual std::vector<std::unique_ptr<Wallet>> getWallets() = 0;
 };
 
 //! Return implementation of Chain interface.

src/interfaces/node.cpp

@@ -279,8 +279,10 @@ namespace {
         }
         std::vector<std::unique_ptr<Wallet>> getWallets() override {
             std::vector<std::unique_ptr<Wallet>> wallets;
-            for (const std::shared_ptr<CWallet> &wallet : GetWallets()) {
-                wallets.emplace_back(MakeWallet(wallet));
+            for (auto &client : m_context.chain_clients) {
+                auto client_wallets = client->getWallets();
+                std::move(client_wallets.begin(), client_wallets.end(),
+                          std::back_inserter(wallets));
             }
             return wallets;
         }

src/interfaces/wallet.cpp

@@ -482,6 +482,14 @@ namespace {
         }
         void flush() override { return FlushWallets(); }
         void stop() override { return StopWallets(); }
+        void setMockTime(int64_t time) override { return SetMockTime(time); }
+        std::vector<std::unique_ptr<Wallet>> getWallets() override {
+            std::vector<std::unique_ptr<Wallet>> wallets;
+            for (const auto &wallet : GetWallets()) {
+                wallets.emplace_back(MakeWallet(wallet));
+            }
+            return wallets;
+        }
         ~WalletClientImpl() override { UnloadWallets(); }
 
         Chain &m_chain;

src/rpc/misc.cpp

@@ -6,6 +6,7 @@
 #include <chainparams.h>
 #include <config.h>
 #include <httpserver.h>
+#include <interfaces/chain.h>
 #include <key_io.h>
 #include <logging.h>
 #include <node/context.h>
@@ -448,12 +449,17 @@ static UniValue setmocktime(const Config &config,
     LOCK(cs_main);
 
     RPCTypeCheck(request.params, {UniValue::VNUM});
-    int64_t mockTime = request.params[0].get_int64();
-    if (mockTime < 0) {
+    int64_t time = request.params[0].get_int64();
+    if (time < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Timestamp must be 0 or greater");
     }
-    SetMockTime(mockTime);
+    SetMockTime(time);
+    if (g_rpc_node) {
+        for (const auto &chain_client : g_rpc_node->chain_clients) {
+            chain_client->setMockTime(time);
+        }
+    }
 
     return NullUniValue;
 }