Doris Tam authored Dec 02, 2020 and Robert Lyon committed Dec 17, 2020

Moving the watchlist delay notification setting from site options from admin settings
to plugin administration under blocktype.

- Moved strings to the blocktype.watchlist lang strings area.
- Removed a set_config call in upgrade.php and added a post_inst method
following other blocktype plugin  post install calls instead.

- Upgrade step to transfer over old site setting 'watchnotification_delay'
to plugin admin, updating the version number too
Change-Id: If388ddd083ceb8f46026fdc138f27ca8c8da5b04