A less ambiguous name for "Market/Client load"

[shsms]

At any installation location, the primary power consumer that the microgrid is meant to support, has been called the market load/client load until now. This name is ambiguous and needs a replacement that's generic and obvious.

[shsms]

This was discussed here: #61 (comment)

and the decision what that the sdk will not support or acknowledge something called the "client load", but will expose methods for users to get these values by implementing higher order functions.