New icon, bug fixes & performance improvements

This update contains a number of bug fixes for older Luna collections and improvements to performance:

• Updated the favicon to be the Luna logo when bookmarked

• Improved loading times within the app

• Fixed a bug that created an error when opening collections

• Fixed a bug that stopped collections from showing on the ‘All collections’ tab

• Fixed a bug that showed error code 500 when editing cards in smart scheduling

• Fixed the review all button being greyed out incorrectly when creating collections

• Fixed start and end date years that were unable to be typed