Arvados » Arvados Workbench 2

As a user, I would like to have a collection versioning tool,
so that I will have access to previous versions of the collection.

Acceptance criteria:
- collection details pane contains version number of the current collection and a "Show all versions" button which brings up a modal
- modal with table
- a table contains columns: Version, UUID, Created at, Modified at
- Open icon (open previous version of the collection)
- past versions of collections are read-only, so the UI needs to have some abilities disabled, e.g. editing name/description/properties, uploading data, removing files, etc See: https://doc.arvados.org/v1.4/user/topics/collection-versioning.html
- collection action menu has an action to snapshot the current version which sets the preserve_version bit. If the user attempts to snapshot the same collection a second time before it has been modified, they are warned that the current version has already been snapshotted and operation has no effect.