Added confirmation step to VBO bulk deletion. #1029

Job	Run time
set_sites	38s
test_phpunit	1m 27s
lint_theme	36s
test_new_site	7m 39s
test_existing_site (biologyvirtualshowcase)	6m 17s
test_existing_site (ccsre)	10m 2s
test_existing_site (cmems)	7m 3s
test_existing_site (hs_testing_sandbox)	7m 9s
test_existing_site (humanbiology)	8m 1s
test_existing_site (language)	9m 25s
test_existing_site (lowe)	6m 11s
test_existing_site (music)	9m 31s
test_existing_site (physics)	12m 39s
test_existing_site (ptarmigan)	6m 33s
deploy_branch	0s
	1h 33m 11s

Provide feedback