Rename getBalance to getExternalBalance

[axic]

It loads an external account and as such this naming reflects it better.

[jakelang]

Perhaps getBalanceAtAddress may make more sense upon initial reading?

[axic]

Good idea, although I'd suggest that a proposal is created which renames all the getExternal<xyz> to a scheme get<xyz>AtAddress

[chfast]

There is a naming convention in RPC that applied here would mix both proposals to getBalanceAt(), but in English it would be better to have getBalanceOf().

[jakelang]

@axic would changing the naming scheme make sense if we want to keep it similar to EVM opcode names?

Or perhaps should we change such names in a later revision where we depart from EVM compatibility?

[chfast]

@jakelang I think "similar" is good enough. It should not be a problem for match mentally BALANCE opcode with getExternalBalance or getBalanceOf.