Rescanning of download page when folder is added

When new folder or the first time user adds permission, we need to rescan the entries in background page on the go to ensure selection is effective and can be choosen by user.
We call the background page and add call rescanning function when scan is started in the select page. Then at a interval of 10s we update the select with all the scanned values.
Fixed Select option was getting duplicate entries.

While the last change where we rediscover the background page and repopulate the select option.
Entries were getting duplicate, Fixed that by putting a check to add only if item isn't there.
Decreased the interval for updating select options
Changed Interval to Timeout as one time execution
Added to remove the file after file is moved
Added to remove the file after file is moved