change "exit format" to "standard outcome"

[geoknee]

[NEW] What is this issue for
Decide on a naming convention that reduces confusion in the statechannels repos (primarily, for now).

[Defined] How will we solve it
A clear and concise description of what you want to happen, which can include implementation suggestions
Include an estimate (~ 1point = 1day)

[Development]
[] This ticket has clearly outlined the expected outcome, and I can complete this ticket with no additional refinement

Additional context Add any other context or screenshots about the feature request here: notion doc, github discussion or ticket

[geoknee]

We like the idea of keeping the naming as is, and aliasing the imports on the consuming side. This is easy to do in Typescipt.

Question: is it also possible in solidity? for example:

import {ExitFormat as StandardOutcome} from '@statechannels/exit-format/contracts/ExitFormat.sol';

[geoknee]

We think the answer is yes

https://docs.soliditylang.org/en/v0.4.24/layout-of-source-files.html

so closing this issue.