Safely Terminate Aggregator

[kimichenn]

Closes #324

We now:

• Terminate aggregator safely and early when targets/matched is hit, and move to CVLoiter, then automatically to AirdropPrep
• Remove the check for whether we are in CVLoiter. If not, we move to CVLoiter then automatically to AirdropPrep

[AskewParity]

Thanks for doing this, it should free a good amount of resources if our CV models are decent Lol.

I think this PR could be accomplished using C++'s thread management itself. That method probably reduces the complexity and increases the stability/reliability of shutting down the threads.

There were originally more comments over specific implementation techniques, but we can revisit them at a later time if we are keeping this solution.

[AskewParity]

Also, while reviewing this PR. I don't think I/we have a good definition of what CVAggregator is supposed to be. It is possible to be initialized multiple times under different circumstances. We should decide on (and document) what CV aggregator is and how it interacts with the mission loop+other things.

What I imagined before now was that CV aggregator was the module that the mission state/loop communicated to in order to access CV pipeline results.

ok after looking for a bit, aggregator is a mess; we should refactor it.

[AskewParity]

Thanks for making this rewrite of the PR. I think it is more maintainable now.

I just have one clerical change to make.