[BUG] Activities: baseline starts/finishes don't match values from SmartPM UI

[HagenFritz]

Current Behavior

I am attempting to recreate this figure:

But for baseline starts and finishes, the values are way off.

Expected behavior

For this specific project, I am plotting 967 starts/finishes, but the SmartPM UI is only showing 464. So my thought is that we are not filtering activities that we probably should.

Steps To Reproduce

Steps to reproduce the behavior:

1. Run python snippets/explore_activities.py and view the activity_distribution.csv file in the references directory.
2. Find the same project on SmartPM and find this figure
3. Export the data
4. Compare Baseline Starts/Finishes

Additional context

Might be worthwhile talking to SmartPM users to see why or why not certain activities would not be included.

[HagenFritz]

The Planned Start/Finishes are also wrong, but only for the month that the data date falls within