devnet c-chain support (#162)

* devnet c-chain support

* etna rpc

Author: rajranjan0608

config.json

@@ -301,6 +301,23 @@
                 "MAX_LIMIT": 1,
                 "WINDOW_SIZE": 1440
             }
+        },
+        {
+            "ID": "CDEVNET",
+            "NAME": "Devnet (C-Chain)",
+            "TOKEN": "AVAX",
+            "RPC": "https://etna.avax-dev.network/ext/bc/C/rpc",
+            "CHAINID": 43117,
+            "EXPLORER": "https://subnets-test.avax.network/c-chain",
+            "IMAGE": "https://glacier-api.avax.network/proxy/chain-assets/main/chains/43113/chain-logo.png",
+            "MAX_PRIORITY_FEE": "10000000000",
+            "MAX_FEE": "100000000000",
+            "DRIP_AMOUNT": 2,
+            "DECIMALS": 18,
+            "RATELIMIT": {
+                "MAX_LIMIT": 1,
+                "WINDOW_SIZE": 1440
+            }
         }
     ],
     "erc20tokens": [