ui: Display XMR view key on bid page

https://monerohash.com/explorer/myoutputs

Shared view key is for the chain B lock tx.

To find the view key for the lock spend tx:
http://localhost:12700/rpc
Monero Wallet
    getaddress
    query_key {"key_type":"view_key"}

basicswap/interface/xmr.py

@@ -181,7 +181,10 @@ class XMRInterface(CoinInterface):
         return edf.scalarmult_B(key)
 
     def encodeKey(self, vk):
-        return vk.hex()
+        return vk[::-1].hex()
+
+    def decodeKey(self, k_hex):
+        return bytes.fromhex(k_hex)[::-1]
 
     def encodePubkey(self, pk):
         return edu.encodepoint(pk)
@@ -216,9 +219,6 @@ class XMRInterface(CoinInterface):
     def lengthDLEAG(self):
         return dleag_proof_len()
 
-    def decodeKey(self, k_hex):
-        return bytes.fromhex(k_hex)
-
     def sumKeys(self, ka, kb):
         return ed25519_scalar_add(ka, kb)