Make getaddressinfo return solvability

src/wallet/rpcwallet.cpp

@@ -3538,6 +3538,7 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
             "  \"address\" : \"address\",        (string) The bitcoin address validated\n"
             "  \"scriptPubKey\" : \"hex\",       (string) The hex-encoded scriptPubKey generated by the address\n"
             "  \"ismine\" : true|false,        (boolean) If the address is yours or not\n"
+            "  \"solvable\" : true|false,      (boolean) If the address is solvable by the wallet\n"
             "  \"iswatchonly\" : true|false,   (boolean) If the address is watchonly\n"
             "  \"isscript\" : true|false,      (boolean) If the key is a script\n"
             "  \"iswitness\" : true|false,     (boolean) If the address is a witness address\n"
@@ -3592,6 +3593,7 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
     isminetype mine = IsMine(*pwallet, dest);
     ret.pushKV("ismine", bool(mine & ISMINE_SPENDABLE));
     ret.pushKV("iswatchonly", bool(mine & ISMINE_WATCH_ONLY));
+    ret.pushKV("solvable", IsSolvable(*pwallet, scriptPubKey));
     UniValue detail = DescribeWalletAddress(pwallet, dest);
     ret.pushKVs(detail);
     if (pwallet->mapAddressBook.count(dest)) {