Show sharees as Avatar-Group

[exalate-issue-sync]

Userstory

As a user I want to see at a glance if an item is shared so that i feel in control of my data and can take further actions.

uses oc component, maybe needs some rework regarding the "expand" animation:
https://owncloud.design/#/oC%20Components/OcAvatarGroup

Acceptance Criterias

• show list of sharees as avatar group
• oc avatar group: if stacked: don't expand on hover (kill the animation of the component/ODS 🥲 )
• wording: change "invited people" in "Shared with"
• display "groups" as different icon (not supported currently) icon: tbd [~tbaader]
• display "federated" as different icon with different color (not supported currently) icon: tbd [~tbaader]
• display "guests" as different icon with different color (not supported currently) icon: tbd [~tbaader]
• display "user" and "groups" in same color
• tooltip: "Click to show all"
• aria property with similar information as in tooltip
• on click: display sharees as list (the one that we currently have)
• add unit-tests