Arvados » Arvados Workbench 2

As a user I would like edit name and description of a collection
so that I can personalize it according to my goals.

Acceptance criteria:
- modal with inputs "Collection name" and "Description"
- collection name must be unique so it need to be validated
- after successful action, snackbar appears with information that "Collection has been edited".

Mockup: https://3czrf1.axshare.com/#g=1&p=4_3_collection&c=1

User flow:

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

2. Edit collection.

3. Click on "Save" button.

4. Collection name is validated.

5. (successful action) Snackbar appears with information that "Collection has been edited".