User Loans Page (Closed Loans Tab) Should Have Own URL

Tested successfully on 22-January Marc Keepper

Users App top level
URL = http://folio-testing.aws.indexdata.com/users?filters=active.Active&query=&sort=Name
Users App, User = Adams, Helene Betsy, Select User Loans page, 3 Open Lons

URL = http://folio-testing.aws.indexdata.com/users/view/b8f8cf7d-fc86-4862-85fc-cd72e0ee369b?filters=active.Active&layer=open-loans&query=&sort=Name

Closed Loan page for the same user is also successful
http://folio-testing.aws.indexdata.com/users/view/b8f8cf7d-fc86-4862-85fc-cd72e0ee369b?filters=active.Active&layer=closed-loans&query=&sort=Name

@Zak Burke Yep - that's the best way. It will need a url to fit to that 'to' attribute, of course. If <Button> is supplied an `href` prop it will render an anchor with button styling - but this might be broken since that functionality wasn't used very often and the styles have gone through quite an overhaul recently.

@John Coburn, I believe the easiest option for enabling Scenario 2, “Right click ‘N Open loans’ to open it in a new tab” is to change the <Button onclick...>NNN Open Loans</Button> elements to <Link to...>NNN Open Loans</Link> elements. Agreed? We could wrap a <Button> in a <Link> but I’m not sure there’s an advantage to that.

Per @Jakub Skoczen, we should keep this story separate from https://folio-org.atlassian.net/browse/UIU-143#icft=UIU-143 (URL for Open Loans Tab). I have added some Notes to the story description above which may inform a general solution, if that's the direction we go.

See comment on https://folio-org.atlassian.net/browse/UIU-143#icft=UIU-143. Not sure if these stories should be combined or left separate at this point.