LP#1884787: update Angular staff client to work with momement-timezone >= 0.5.29

LP#1884787: update Angular staff client to work with momement-timezone >= 0.5.29

Now that moment-timezone ships with an index.d.ts (as of 0.5.29), this
patch updates how moment-timezone is imported and used since we
now have to care more about type-checking.

Among other things, this updates the ScheduleRow interface to account
for the fact that with the stricter type checking coming from the recent
moment-timezone change, ScheduleRow.time as a moment.Moment object
cannot be in the same interface as a string index type.

To test
-------
[1] Make sure that results of  'npm run test' are clean.
[2] Create a reservation or two in the booking interface and
    verify that scheduled reservations show up on the grid
    in the create reservations page.
[3] Verify that the icons indicating whether resources are
    available or not at a given time are correct on the
    create reservations grid.

Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>
Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu>