Fixing time stamps for the Multiscope pilot data

[jkim0731]

Getting ophys timestamps from utilities assumed 4 FOVs (8 planes).
For pilot data, this may not be true (can have any number of FOVs).

Added a function to get the number of FOVs,
and applied this number for getting ophys frames timestamps.

[jkim0731]

Seems like there is a lot of conflicts to resolve with the main branch - should we just use this branch for learning mFISH data?

[matchings]

@jkim0731 yes we need to stay on this branch for learning mFISH. The main branch is still configured for Visual Behavior project dataset, and needs to stay like that since we are still working on the platform paper. it is unfortunate to have two divergent branches, but it is what it is. We can clean it up and make it work for either project once the platform paper is done, but i dont want to change anything on main until then.

thanks for making this function more flexible though!