Suggest matches for new element subject

[CSchmitz81]

As the user types the new subject into the new element dialog a search should be run for matching elements with the expected type, which should then be displayed as previews within the new element dialog. The suggested elements should be limited to the top 12, arranged in a grid if the dialog is wide enough, similar to the home screen. If an element is clicked it should be opened to show its element details dialog. If the element is not already a child (has the same parent element) there should be a button below the suggested element to link that element as a new child, unless the type doesn't support multiple children. Elements which are already children can have the same button in a disabled state, but should show a tooltip when moused over which states that it's already linked to the same element.

If #55 isn't implemented, element search can be added to the list loader returning newly generated list in the same way suggested results are generated.

[CSchmitz81]

Requires #73 to be implemented

[CSchmitz81]

Requires #116 to be implemented, which should cover listing the elements, but some additional visual changes will need to be made, as covered in the description.