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

- 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