Remove flagged experiments from platform paper function, and boolean zen!

[alexpiet]

• [x] Creates a function loading.get_flagged_ophys_experiment_ids() for OEIDS that are in the release dataset but have been flagged for removal
• [ ] Enumerates all the oeids in that function (@matchings, please add yours)
• [x] Adds a toggle option for loading.get_platform_paper_experiment_table(remove_flagged=True) that filters out the flagged oeids.
• [x] fixes about 10,000 boolean zen violations. if variable == True is logically equivalent to if variable.