[RPC, Wallet] Move RPC dispatch table registration to wallet/ code

Allow extending the rpc dispatch table by appending commands when server is not running.

src/test/test_bitcoin.cpp

@@ -54,6 +54,7 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
     const CChainParams& chainparams = Params();
 #ifdef ENABLE_WALLET
         bitdb.MakeMock();
+        walletRegisterRPCCommands();
 #endif
         ClearDatadirCache();
         pathTemp = GetTempPath() / strprintf("test_bitcoin_%lu_%i", (unsigned long)GetTime(), (int)(GetRand(100000)));