Problem: GetEthBalance blocks the GameThread cronos-labs#270

Solution: convert sync apis to async

change GetEthBalance to async

change GetBalance to async

convert GetNFTSupply to async

convert GetNFTOwner to async

convert GetNFTCollection to async

convert GetNFTDenom to async

change GetNFTDenomByName to async

convert GetNFTAllDenoms to async

refactor sendamount

make SendAmount to async

convert GetNFTToken to async

convert Erc20Balance to async

convert Erc721Balance to async

convert Erc1155Balance to async

convert Erc1155BalanceOfBatch to async

convert Erc721Name to async

convert Erc721Symbol to async

convert Erc721Uri to async

convert Erc721GetApproved to async

convert Erc721IsApprovedForAll to async

convert Erc1155Uri to async

convert Erc1155IsApprovedForAll to async

convert Erc721Owner to async

convert Erc721TotalSupply to async

convert Erc721TokenByIndex to async

convert Erc721TokenOwnerByIndex to async

convert Erc20Name to async

make Erc20Symbol to async

make Erc20Decimals to async

make Erc20TotalSupply to async

make Erc20Allowance to async

tidy up comment