Potential input checking and error handling improvements

Work-in-progress

Purpose

The purpose of the following potential improvements is to make it easier to stand up and use an ActivitySim model. This list of improvements is in response to phase 6a task 7.

Potential Improvements

Idea	Level-of-effort	Notes
Add checking of zone and synthetic population input data, such as each household belongs to a zone and each person belongs to a household.
Add checking of expression formatting and settings formatting, such as expressions can be successfully parsed by Python.
Add more error handling and smarter messages, logging, etc., such as when submodel yaml files cannot be found.
Add functionality for when no alternative is found to try and figure out why, such as which terms in the utility turn off all alternatives.
Make usability improvements to the pipelining, such as reduce/remove duplicate table fields and make use of categorical types to improve runtime and
Improve the user documentation related to using the data pipeline.