Concept for Item List

Requirements:
* Sorting
* Filtering
* Paging
* Configuration in schema that allows user to choose a binary field that is used for icon/preview. For images, the image is shown. For other binaries, a predefined icon based on the file type is shown instead.

From Mesh we need the following features:
* Sorting https://github.com/gentics/mesh/issues/486
* Custom attributes in schemas https://github.com/gentics/mesh/issues/93

Start by reviewing the item-list requirements and the linked Mesh issues 486 and 93 to understand the required upstream sorting and schema support. Done means the UI provides sorting, filtering, paging, and schema-driven binary previews or file-type icons.

Written by the indexing model from the issue text.