Paper UI: Filtering mechanisms for Item list

[kaikreuzer]

Currently, the Item list is a flat list and if there are many items defined, it is almost unusable, because the user cannot find the one(s) he is looking for.

I would therefore suggest the introduction of some clever search and filter mechanism:

• There should be a free-text search field at the top, similar to what we have on the Extensions tab.
• It should be possible to filter for items that belong to a specific GroupItem. For this, a selection box with GroupItems could be provided.
• If a GroupItem is selected, it should automatically set the filter for this GroupItem.
• Selecting an Item should hence NOT go to the edit page anymore - instead, an "edit" button should be introduced, similar to what we have on Things.
• Another filter for item types could be added, next to the group filter.
• To quickly get rid of the filters, there must also be a "clear filter" button somewhere.
• When clicking the "+" icon for creating a new item, the current settings of item type and GroupItem should be respected, i.e. the item creation page should be pre-filled with the type and having the group item listed as a parent group.

[kubawolanin]

For what I have seen PaperUI is using Angular Material framework. I may suggest using md-autocomplete component instead of md-select. I'm involved in HABPanel more nowadays (need to finish a few things I'm working on), but I may jump in later on.