User-friendly data loader error messages

[amabdallah]

Is your feature request related to a problem? Please describe.

As the WaDE program grows and potentially new interns and employees work on loading data to the database, we need more user-friendly data loader error messages that are self-explanatory in plain English.

Describe the solution you'd like
There should be a clear message that lists exactly what the issue is such as missing values in a required field at line # in the x input file. The message should hint at or suggest a solution.

Additional context
This error message for example would be scary for an intern (lots of red stuff) and it's not clear what's going on. An intern trying to load data to WaDE should not need to know the ins and outs of the database to load data. All they need to know is the list of required and optional fields for each input file according to these templates. Input data is imperfect, so the user-friendly data loader error messages should help the user in knowing what is wrong and where it is and how to fix it.
https://github.com/WSWCWaterDataExchange/MappingStatesDataToWaDE2.0/tree/master/DataDict

[amabdallah]

As part of a larger work estimate, DPL estimated this task would take 1.3 weeks of work. See details here
We decided to put this task on hold until additional funding is available.