Refactor & modularize functions in datasets/optical_physiology/data_formatting.py

[DowntonCrabby]

Describe the use case that is addressed by this refactor.
Many of the functions are quite large and unwieldy and would greatly benefit from modularization (breaking them down into smaller & more discrete functions). Additionally the documentation should be updated to provide better information on function outputs. For example if a function is adding columns to a dataframe the documentation should give the new column names, data types and column descriptions.

Describe the solution you'd like
The following functions to be refactored and to be split into smaller more discreet functions:

• get_event_timestamps: could be made into smaller functions to get specific types of events instead of a long series of if statements.
• get_stimulus_response_xr: break this one up into component parts. Its very long and unwieldy
• get_p_value_from_shuffled_spontaneous: break up into smaller functions that are well documented
• get_stimulus_response_df break up into component functions

Additional context
We would like to make a push to refactor and modularize lots of code that had just been ported over from Visual Behavior Analysis, to improve it and make it more readable.

Do you want to work on this issue?
Are you willing and able to work on this refactor?