add ability to clear sub until there's nothin left

Signed-off-by: arghdos <arghdos@users.noreply.github.com>
major updates
--switched to processed flag in order to not remove reddit entries
--store channel url as well (so we don't have to request it on another thread, hopefully fixing that weird Requests bug)
--add/remove black/whitelist by id

Signed-off-by: arghdos <arghdos@users.noreply.github.com>