Arvados » Arvados Workbench 2

As a user I would like to share my collection with another user
so that other people may have access to my collection

Acceptance criteria:
- I can trigger sharing operation on a collection (context menu in the table)
- I can select target users in a modal dialog
- Project is shared
- Permission handling
- Confirmation messages

User flow:

1a. Right click on collection inside the table and choose "Share".
1b. Click on "More options" icon in the table and then choose "Share".

2. Popup appears where user has possibility to specify wanted users.

3. Snackbar appears in the bottom of the page with the information that "Collection has been shared"