Fixed issues with plan duplicattion, plan visibility and plan download ...

updated share visibility message and updated threshold to 50% done instead of 1 question answered

added debounce to new plan to prevent multiple ajax calls for available templates

fixes to Plan download and share pages

fixed issue with plan duplicate/copy

fixed issue with plan duplication test

placed 50% plan visibility threshold in app config

fixed linter issue

added percentage sign to visibility rule description

tweak to js to hide instead of fadeout on load

Bootstrapping and ES6 of the Plan Download page DMPRoadmap/roadmap#561. ...

- Renamed show_export.html.erb to download.html.erb (updated controller, policy, links and route)
- Renamed export_settings.js to download.js and dropped unused auto-save JS (no longer a part of wireframes)
- Bootstrapped page html

changed name of show_export to download to match UI terminology. Bootstrapped download page

Added ES6 JS for download page and made tweaks to the format