Add User Views - allow user specific views - columns, sorting, filtering

[EricaW (Erica Weinberg)]

Allow users to control column view, order, sorting without impacting other users - within a given view, [beyond just creating a separate view tab (which we don’t want a ton of)]. Right now changes to columns impact other users - some of which carries across views as well. This would be both for item and subitem level. Allow each user to make their own and choose whether to share with other teammates (other project management tools offer similar feature)