Sort accounts by networks

[maciejhirsz]

For the functionality it doesn't matter very much, but users (even very technical users) can be unaware that all accounts work with any Ethereum-like network. Having a dropdown of networks that an account can be assigned to would go a long way here.

[tomusdrw]

We could probably detect a mismatched chain_id in case non-replay protected transaction is being signed or a transaction for different chain.

[lexfrl]

I think it could be considered as "implemented" in the 2.0 @debris @maciejhirsz @tomusdrw