Get single post from API by id and query params; Auto-sort posts list

closes #2883, closes #2951
- introduce custom findQuery in ApplicationAdapter
- posts/post route and editor/edit route now use custom findQuery to find a single post by id with query params
- create a sorting function in PostsController for out-of-order loading
- refresh updated posts in posts.index to make PostsList highlight latest draft after returning from a save in editor
Merge pull request #2884 from darvelo/sort-posts-list

Get single post from API by id and query params; Auto-sort posts list