Homogenize step and event

[zmorris248]

If this feature request related to a problem? Please describe.

To make our schema more understandable, we want to use either 'event' or 'step' but not both, since the represent the same thing, which is a part of a 'study' Therefore whichever one we decide on, we change all references of the other to the chosen one in all tables and functions.
Alternatives Considered If Applicable

Rationale

Implementation Ideas

Additional Context