Events for updating exist, but they lack context. This adds args so that plugins can detec t what plugin/theme is being installed. Additionally, events for bulk actions, deleting and that and install is starting didn't exist, so this adds them.
Fixes#37512.
Props DavidAnderson, and ocean90, swissspidy for review.
Built from https://develop.svn.wordpress.org/trunk@38175
git-svn-id: http://core.svn.wordpress.org/trunk@38116 1a063a9b-81f0-0310-95a4-ce76da25c4cd