feat: add missing config metric

[junaidk]

sample metric

# HELP cosmos_ibc_config_missing Returns if the rpc config is missing for a channel.
# TYPE cosmos_ibc_config_missing gauge
cosmos_ibc_config_missing{chain_name="agoric",client_id="07-tendermint-75"} 0
cosmos_ibc_config_missing{chain_name="akash",client_id="07-tendermint-184"} 1
cosmos_ibc_config_missing{chain_name="andromeda",client_id="07-tendermint-9"} 1
cosmos_ibc_config_missing{chain_name="archway",client_id="07-tendermint-0"} 0
cosmos_ibc_config_missing{chain_name="archway",client_id="07-tendermint-105"} 0
cosmos_ibc_config_missing{chain_name="archway",client_id="07-tendermint-106"} 0
cosmos_ibc_config_missing{chain_name="archway",client_id="07-tendermint-12"} 0
cosmos_ibc_config_missing{chain_name="archway",client_id="07-tendermint-16"} 0
cosmos_ibc_config_missing{chain_name="archway",client_id="07-tendermint-17"} 0
cosmos_ibc_config_missing{chain_name="archwaytestnet",client_id="07-tendermint-121"} 1
cosmos_ibc_config_missing{chain_name="archwaytestnet",client_id="07-tendermint-144"} 1
cosmos_ibc_config_missing{chain_name="archwaytestnet",client_id="07-tendermint-167"} 1
cosmos_ibc_config_missing{chain_name="axelar",client_id="07-tendermint-160"} 1
cosmos_ibc_config_missing{chain_name="axelartestnet",client_id="07-tendermint-1073"} 1
cosmos_ibc_config_missing{chain_name="bitcanna",client_id="07-tendermint-83"} 1
cosmos_ibc_config_missing{chain_name="bitsong",client_id="07-tendermint-80"} 1
cosmos_ibc_config_missing{chain_name="celestia",client_id="07-tendermint-77"} 1
cosmos_ibc_config_missing{chain_name="comdex",client_id="07-tendermint-189"} 1
cosmos_ibc_config_missing{chain_name="composable",client_id="07-tendermint-143"} 1

[junaidk]

I will create separate PR to fix CI lint issues