major updates to stimulus presentations data formatting

[matchings]

• modified functions to add trials_id to stimulus_presentations - one adds info just for the change and sham change (go/catch) trials, such as whether it was a hit or miss, another adds info across all stimuli that belong to a behavioral trial, such as whether it was aborted or autorewarded
• adds function to label the stimulus count within each trial
• modified function to add could_change column which indicates whether a stimulus presentation could have been a change based on known change trial distribution and whether there had already been a change or lick on that trial
• add functions to get time from last change / omission / lick / reward, or the number of stimuli since the last event
• add columns for whether a stimulus is pre / post change or omission
• add functions to implement multiple of the above annotations: add_timing_info_to_stimulus_presentations and add_behavior_info_to_stimulus_presentations

TODO: add notebook demonstrating use and validation of each function