import inquiry form data (.xls, .xslx, SQLite, .csv, ...)

[rkrenn]

Exporting data of inquiry forms was added in 2019 ( https://github.com/phoenixctms/ctsms/issues/85 ).

This ticket is to track implementation of a importer for inquiry data. The functionality should correspond to the eCRF data importer requested in https://github.com/phoenixctms/ctsms/issues/104 .