Refactor: Move Input Validation Into Function

[DiogenesAnalytics]

Problem

The JS code responsible for "validating" form inputs is being duplicated in the event listeners for the "Send" and "Download Form" button respectively.

Code:

• https://github.com/DiogenesAnalytics/parley/blob/b93298b144af0b5170e5c0b8fca2280b6d921479/scripts/form.js#L333-L391
• https://github.com/DiogenesAnalytics/parley/blob/b93298b144af0b5170e5c0b8fca2280b6d921479/scripts/form.js#L400-L429

Solution

Refactor into a single function (e.g. validateForm()).