lp1827942: prevent clicking outside an Angular modal from closing it

lp1827942: prevent clicking outside an Angular modal from closing it

I added a new property to the "options" object inside the "open"
function, which resides in the dialog.component.ts. The static string
inside the backdrop property makes the form stay, even if the backdrop
is clicked.

Signed-off-by: Zavier Banks <zbanks@catalyte.io>
Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>