Make `getTimeStamp` return `std::chrono::time_point`s

https://github.com/AerospaceNU/better-engine-control-software/blob/11ed3287302c9fbaf08342e43a87ac04023255a6/src/utils/ECSUtils.cpp#L44-L48

remove the `time_since_epoch` and `count` calls, just use the type from `now`
this will require some fixing of `getTimeStamp`'s call sites
you would also have to implement the `time_since_epoch` and `count` calls when we serialize the timestamp back to the operator