Potentially add Ethereum ChainId to repo server API fetch

[JamesSmartCell]

There is a potential ambiguity with fetching Tokenscripts from the server - a developer may have a different tokenscript for the same contract address on different networks.

It's unlikely to happen for a while but may be an issue for native action only scripts, and tokens on various Plasma chains which have the same address (assuming Plasma maintains the same mechanism for creating contract addresses).