Behavior stimulus table should include passive time period

**Is your feature request related to a problem? Please describe.**
When attempting to generate a stim table for our ecephys project, whose pickle file includes both passive and active stimulus epochs, the resulting behavior table does not include the passive epochs.

**Describe the solution you'd like**
[Here](https://github.com/AllenNeuralDynamics/aind-metadata-mapper/blob/e8f978329ef1a53cbd1ce5c6d3439ad909298c6c/src/aind_metadata_mapper/open_ephys/utils/behavior_utils.py#L886)
A passive dataframe should be generated from the information in `pkl['items']['behavior']['items']` and then joined with the existing stimulus dataframe.

**Describe alternatives you've considered**
We could possibly generate two different stim tables?

**Additional context**
N/A