expose exitCode in awaited result

[SuperchupuDev]

useful to have so that users dont need to do await result; result.exitCode

[43081j]

it probably does make sense to have exit related properties copied onto here

e.g. exitCode, signalCode (when we add it), killed, etc

needs some discussion i think

[VanTanev]

Just fyi, I was confused by this as well, but you basically never need to do await result; result.exitCode - it is going to be zero!

When the subprocess returns non-zero exit code, tinyexec will throw NonZeroExitError. So, you can read a non-zero exitCode only when you wrap the await in try-catch.

[SuperchupuDev]

not if you set throwOnError to false in the options