Reorganize reward delivery times

[alexpiet]

Instead of having all rewards grouped together as "right_reward_delivery_time" and then using the "data" column for annotating earned, manual, and auto, we could break them out as separate events.

Note that we could also do this at the level of the NWB - have separate acquisition time series for manual and earned. What do you think @rachelstephlee @Ahad-Allen

[rachelstephlee]

IMO it might be too much for this to be done in the level of NWB-- if we have slightly different type of task or different type of rewards, we'll have to edit the NWB packaging all over again.

to be clear-- you mean that this is a problem for df_events, correct?

just want to make sure i can replicate this on my end before i give design decisions.

[Ahad-Allen]

If these will vary by project then I think it makes more sense to place them all in the reward_delivery_time as it makes scripts and tools able to be general purpose more easily. If there is unlikely to be much variance though, I think we can create a separate time series for each of these.