Alias "blech32" to "bech32" for address creation

This is technically not 100% correct since if blinded addresses are
turned off, it will create a normal address for "blech32".
But it's the simplest thing to do.

src/outputtype.cpp

@@ -16,6 +16,7 @@
 static const std::string OUTPUT_TYPE_STRING_LEGACY = "legacy";
 static const std::string OUTPUT_TYPE_STRING_P2SH_SEGWIT = "p2sh-segwit";
 static const std::string OUTPUT_TYPE_STRING_BECH32 = "bech32";
+static const std::string OUTPUT_TYPE_STRING_BLECH32 = "blech32";
 
 bool ParseOutputType(const std::string& type, OutputType& output_type)
 {
@@ -25,7 +26,7 @@ bool ParseOutputType(const std::string& type, OutputType& output_type)
     } else if (type == OUTPUT_TYPE_STRING_P2SH_SEGWIT) {
         output_type = OutputType::P2SH_SEGWIT;
         return true;
-    } else if (type == OUTPUT_TYPE_STRING_BECH32) {
+    } else if (type == OUTPUT_TYPE_STRING_BECH32 || type == OUTPUT_TYPE_STRING_BLECH32) {
         output_type = OutputType::BECH32;
         return true;
     }

test/functional/feature_confidential_transactions.py

@@ -104,6 +104,12 @@ def run_test(self):
         print("Testing wallet secret recovery")
         self.test_wallet_recovery()
 
+        # Test that "blech32" gives a blinded segwit address.
+        blech32_addr = self.nodes[0].getnewaddress("", "blech32")
+        blech32_addr_info = self.nodes[0].getaddressinfo(blech32_addr)
+        assert_equal(blech32_addr_info["iswitness"], True)
+        assert_equal(blech32_addr_info["confidential"], blech32_addr)
+
         print("General Confidential tests")
         # Running balances
         node0 = self.nodes[0].getbalance()["bitcoin"]